JP2009222285A - Air heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air heating device free from accumulation of condensate inside of the heating device. <P>SOLUTION: A steam supply pipe 2 is connected to an inlet header 8 of a heat exchanger 1. A steam ejector 4 is disposed in the steam supply pipe 2. A simplified steam trap 7 composed of a float 14 and an orifice plate 15 is disposed in a fin tube 6. A condensate storage container 10 and a steam trap 5 are connected to an outlet header 9 of the heat exchanger 1. The condensate in the fin tube 6 is allowed to quickly flow down into the condensate storage container 10 by the simplified steam trap 7, so that it does not remain inside of the heat exchanger 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

 The present invention relates to an air heating apparatus that heats air using steam as a heat source, and more particularly to an apparatus that does not retain condensate as condensed water of steam inside the heating apparatus.

The fin tube type air heating device controls the supply amount of steam to the heating device with a regulating valve, and also uses a check valve and a thermal valve together with the heating device so that when the inside of the heating device becomes vacuum, the check valve Prevents the condensate from being discharged to the outside by opening the valve and sucking outside air into the heating device.

 In this air heating device, there is a problem that the condensate cannot be completely discharged from a plurality of fin tubes, that is, some of the thin tubes. This is intended to discharge the condensate generated inside the plurality of fin tubes attached between the inlet header and the outlet header to the outside with one steam trap attached to the lower part of the outlet header. When the condensate is not present in the fin tube near the steam trap and is filled with steam, while the fin tube located away from the steam trap is filled with condensate, the steam trap remains closed. This is because the condensate of the fin tube at a distant position cannot be discharged.

If condensate stays inside the heating device, it will stay until the next operation of the heating device, corrodes the inside of the heating device, and in some cases opens holes in the fin tubes and damages them.
Japanese Patent Publication No.51-31998

The problem to be solved is to obtain an air heating device that does not retain condensate inside the heating device.

 In the present invention, air passing through a heat exchanger composed of a plurality of thin tubes is heated with heating steam supplied via a steam supply pipe, and the condensed water from which the steam is deprived of heat is condensed from the steam trap. In the case of discharging to the outside, a simple steam trap that opens when condensate flows in and closes when steam flows in is arranged in a plurality of narrow tubes.

  The air heating apparatus of the present invention has a simple steam trap that opens when a condensate flows in and closes when a steam flows in the inside of the plurality of narrow tubes. It is possible to reliably discharge the condensate generated from wherever it is.

  In the present invention, a simple steam trap is arranged inside a plurality of thin tubes. As the simple steam trap, an open / close valve based on a difference in specific gravity between condensate and steam, or condensate and steam is used. A conventionally known steam trap such as one that opens and closes based on the temperature difference can be used.

  In this embodiment, a heat exchanger 1 that heats air passing therethrough, a steam supply pipe 2 that supplies steam to the heat exchanger 1, a control valve 3 and a steam ejector 4 that are attached to the steam supply pipe 2, and heat The steam trap 5 connected to the outlet side of the exchanger 1 constitutes an air heating device.

  An inlet header 8 is arranged at the upper part of the heat exchanger 1 and connected to the steam supply pipe 2, and an outlet header 9 is arranged at the lower part and connected to the steam trap 5. Between the outlet header 9 and the steam trap 5, a condensate reservoir 10 for temporarily storing the condensate flowing down from the outlet header 9 is disposed. A pipe line 11 is connected to the upper left part of the condensate reservoir 10, and its upper end is connected to the suction chamber 12 of the steam ejector 4.

The steam supplied from the steam supply pipe 2 flows from the steam ejector 4 and the inlet header 8 through the fin tube 6 of the heat exchanger 1 downward from above, and exchanges heat with the air passing in the direction of the arrow 13. Condensate is formed and discharged from the outlet header 9 through the condensate reservoir 10 and the steam trap 5 to the outside.

 In the fin tube 6 of the heat exchanger 1, a spherical float 14 is disposed in a free state, and an orifice plate 15 provided with a through hole immediately below the float 14 is disposed. When condensate accumulates in the fin tube 6, the float 14 floats by its own buoyancy and opens away from the through hole of the orifice plate 15, thereby allowing the condensate to flow down to the outlet header 9. In this embodiment, the float 14 and the orifice plate 15 constitute a simple steam trap 7.

When the air is heated by the heat exchanger 1, the air flowing down in the direction of the arrow 13 is heated by the steam having a predetermined pressure supplied from the steam supply pipe 2 and the inlet header 8 into the fin tube 6. Steam deprived of heat by heating becomes condensate and flows down from the simplified steam trap 7 to the outlet header 9 and is further removed from the condensate reservoir 10 and the steam trap 5 to the outside.

In the condensate reservoir 10, a part of the condensate that has flowed down is re-evaporated to become re-evaporated steam, and is stored above the container 10 and sucked into the suction chamber 12 of the steam ejector 4. A predetermined pressure gradient is formed between the inlet header 8 of the heat exchanger 1 and the condensate reservoir 10, and the condensate in the heat exchanger 1 flows down into the condensate reservoir 10 with certainty. Condensate does not remain in the exchanger 1.

The block diagram which shows the Example of the air heating apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Steam supply pipe 3 Control valve 4 Steam ejector 5 Steam trap 6 Fin tube 7 Simplified steam trap 8 Inlet header 9 Outlet header 10 Condensate reservoir 12 Suction chamber 14 Float 15 Orifice plate

Claims (1)

The air passing through the heat exchanger consisting of a plurality of thin tubes is heated with the heating steam supplied through the steam supply pipe, and the condensed water is extracted from the steam trap. An air heating device, wherein a simple steam trap that opens when a condensate flows and closes when a steam flows is disposed in a plurality of thin tubes.

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