FR2524172A1 - DEVICE FOR REGULATING THE FLOW OF A CIRCULATING AGENT IN AN ENCLOSURE - Google Patents

Abstract

THE INVENTION CONCERNS A DEVICE FOR THE REGULATION IN DIRECTION AND OR IN QUANTITY OF A FLOW WHICH CIRCULATES IN AN ENCLOSURE. THE FLOW OF A PROTECTIVE GAS IN A CONTINUOUS OVEN COMBINED WITH A COOLING ZONE CAN MORE PARTICULARLY IN SUCH A DEVICE. ENCLOSURE 1 HAS INPUT 6 AND OUTPUT 4, 5 OPENINGS CONNECTED TO A TRAFFIC LINE FOR THE AGENT FLYING IN THE ENCLOSURE, AND AT LEAST ONE OUTPUT, FROM WHICH A PART OF THIS AGENT EXIT. VALVES 7, 8 ARE AVAILABLE AT THE INPUT AND OUTPUT OPENINGS WHICH ARE FUNCTIONAL DEPENDENT ON THE QUANTITY OF AGENT LEAVING THE ENCLOSURE. BY THIS MEANS, THE FLOW OF PROTECTIVE GAS THAT EXITS FROM THE COOLING ZONE OUTLET CAN BE REGULATED IN PARTICULAR, SO AS TO AVOID THE ENTRY OF AIR IN THE COOLING ZONE.

Description

The invention relates to a control device in the direction and / or in

  quantity, of the flow of an agent circulating in an enclosure, provided with inlet and outlet openings connected to a pipe for the circulation of the agent of the enclosure, and at least one enclosure outlet by which leaves a part

of this agent.

  Devices of this type are for example required in cooling installations which in turn are connected to the inlet and outlet of a continuous furnace for the heat treatment of parts under air-fired protective gas, where the gas protector forms a curtain of flames at the entrance of the rooms in the oven, and at the exit of the rooms out

  of the cooling device and where provision is made

  tif to circulate and cool the protective gas.

  In cooling devices known from the prior art, the direction of the protective gas passing through the cooling device is regulated by guide plates disposed at the inlet of this gas in the cooling device.

  cooling, depending on the temperature of the gas

  burned, on leaving the cooling device, by

the arrival of the outside air.

  With these guide plates it is impossible to act frequently and efficiently on the flow, in particular for the low settings of the guide plates. Moreover, the sheets of this type are bulky, and their installation is not always easy.

  possible for construction reasons.

  The object of the present invention is to propose a regulating device that operates without using sheet metal

guidance.

  The problem is solved according to the invention with a device characterized in that valves are arranged at the inlet or outlet openings of the enclosure, and that these valves are actuated according to the quantity of the agent

  that goes out through the exit opening of the enclosure.

  Although the device according to the invention is preferably used with a continuous oven for the treatment

  thermal parts combined with a cooling device

  This use is not exhaustive.

  It is generally suitable for regulating the flow of an agent circulating in an enclosure, a chamber,

  container, where the agent is compressible or incompetent

  particularly pressible a liquid or a gas.

  The invention will be better understood by means of the

  Hereinafter, a preferred embodiment of the invention is

  tion, with reference to the appended drawing which represents a device for regulating the flow of a circulating agent at

inside an enclosure.

  A cooling device for continuous furnace open at the inlet and outlet, for heat treatment of parts under protective gas fuel in air is described

  in the German application DE 26 01 658.

  The protective gas forms a curtain of flames in the

  parts in the furnace and out of the cooling zone parts, and there is provided a device for circulating and cooling the protective gas in the device

cooling.

  A cooling system of this type is

  schematically represented in the single figure annexed

  closed loop (1) constituting the cooling zone

  It has an inlet (2) for cooling parts.

  dir and an outlet (3) for cooled parts These parts,

  not shown are transported to the cooling zone.

  by a feeding installation At its entrance (2), the

  cooling zone is connected directly to a continuous oven

  for the heat treatment of the parts, and the installation of

  mentioned above generally runs as well

  the oven as the cooling zone.

  The opening sections of the entrance (2) and the

  outlet (3) are dimensioned such that a protective gas

  fuel, hydrogen for example, protecting the treated parts from oxidation, can arrive by the exit

  (3) in the open air and through the inlet (2) in the continuous oven.

  The protective gas entering the continuous furnace is burned by a flame curtain located at the inlet opening of the rooms to prevent the ingress of harmful outside air. The same device is at the outlet (3) of the protective gas is brought back to A to replace the quantity that has

been burned.

  The protective gas is constantly blown into the air

  interior of the enclosure (1) For this purpose, the enclosure (1) is provided,

  as on the schematic representation of the example of

  two outlet openings (4) (5) and an inlet opening (6) which are connected to each other by a pipe

  circulation (10) of the protective gas or other agent.

  In the pipe (10) there is a pump (9) which provides blowing The pipe (10) may further contain a cooling device (not shown) for the agent flowing The openings (4) (5) are located on both sides of the opening (6) preferably symmetrically

right here.

  On the path of the circulation pipe (10) and directly after the outlet openings (4) (5),

  valves (7) (8) actuated by servomotors (18) (19).

  The agent in the chamber (1) is expelled through the openings (4) (5) and flows through the open valves (7) (8),

  by the pump (9), possibly by a cooling device

  by a pipe (10) and an inlet opening (6)

and again in the bedroom (1).

  The operation can also be reversed, in this case the inlet opening (6) is transformed into the outlet opening, and the outlet openings (4) (5) into the inlet openings. The agent flowing through the inlet opening (6) is divided according to the distribution of pressure in flows

  of equal flow each time, indicated by the arrows (11) (12).

  The agent flowing through the outlet openings (4)

  (5) is constituted by the collection of flows representing

  arrows (13) (14) and (15) (16).

  If the same flow is sucked through the openings (4) (5), the flow rate (11) must be identical to the flow rate (14) and the flow rate (12) must be identical to the flow rate (15). This means that the flows

  (13) and (16) must be zero and no outflow occurs.

  kills between the inlet (2) and the outlet (3).

  If the valve (8) is closed, the flow entering through

  the opening (6) must be identical to that drawn by the

green (4).

  But if the flow (11) is identical to the flow (14),

  the additional flow (13) must be sucked in through the inlet (2).

  The flow (12) that is not sucked by the opening (5) flows through the outlet (3). As a result, a flow or a current

  crosses the enclosure (1) from the inlet (2) to the outlet (3).

  Conversely, if the valve (8) is open and the valve (7) closed, a flow occurs in the opposite direction, from the

output (3) to the input (2).

  According to the corresponding rules of variation of

  amount of agent sucked through the openings (4) (5), resulting in

  the corresponding operation of the valves (7) (8) (by the

  servomotors (18), (19)), it is possible to establish

  of the enclosure (1) a variable flow of the input (2) to

  the exit (3) or in the opposite direction.

  If the quantity of agent leaving the outlet (3) is detected by a measuring technique by means of a probe (17), the valves (7) and (8) can be automatically controlled by the servomotors (18) ( 19) and the probe (17) to maintain

a determined value of the flow.

  The control device described above is,

  preferably applied to continuous furnaces with

  cooling combined with a room heater.

  In order to protect the hot parts in the oven and in the cooling zone from the oxidizing flow, it is necessary that the inlet of the oven and the outlet of the cooling zone (3) are constantly protected by a flow of protective gas of a specific quantity, that is why the shielding gas that comes out is burned in a curtain of flames

  by the arrival of outside air (as in the German application

  from DE-PS 26 01 658) The amount of gas that comes out can be

  cilification increased or decreased by disturbances occurring outside or inside the oven In the latter case, that is to say, for a small amount of protective gas at the outlet, which corresponds to insufficient coverage outlet (3) of the cooling zone, there are the risks of an air inlet into the cooling zone and a

  oxidation of parts that are not yet cooled.

  With the aid of the described control device it is possible to prevent the entry of harmful outside air by appropriate adjustment.

  the amount of protective gas leaving the outlet (3).

  For this purpose, and in a manner known per se and therefore not

  a probe (17) is placed in an exhaust channel of

  gas, connected to the outlet (3), detecting at this point the temperature

  The temperature of the exhaust gas and air mixture is adjusted to the amount of the supplied air, the value of However, if the amount of air that generates the flame curtain and the heating value of the protective gas is constant, the temperature detected in the

  exhaust gas channel is a reference value for the quan-

  protective gas that exits through the outlet (3).

  As a result, the quantity of protective gas leaving is regulated by detection of this temperature by means of the probe (17) and then the control servomotors (18) (19) which at their

  turn the valves (7) (8>.

  The flame curtain described above and occurring at the outlet (3) and the furnace inlet (not shown) is not

absolutely necessary.

  It is also possible to replace the use

  nitrogen as a protective gas, by a flow of

  non-combustible sensor which will also prevent the entry of outside air The sensor (17) is not necessarily a temperature sensor The quantity of protective gas flow at the outlet (3) can be measured by another means, by

  example by a flow measuring instrument.

Claims (5)

CLAIMS. Control device in direction and possibly in quantity, the flow of an agent circulating in an enclosure, provided with inlet and outlet openings connected to a pipe for the circulation of the agent of the enclosure and of at least one enclosure outlet through which a portion of this agent exits, characterized in that valves (7) (8) are arranged at the inlet or outlet openings (4) (5) (6) and that valves are functionally dependent on the amount of agent exiting the outlet (3) of the enclosure (1).   2 Device according to claim 1, characterized in that the enclosure (1) comprises an inlet opening (6) and   two outlet openings (4) (5) for the circulation agent.   3 Device according to any one of the claims   I and 2, characterized in that the outlet openings (4) (5)   are arranged symmetrically with respect to at least one opening entrance (6).   4 Device according to any one of the claims   1,2,3, characterized in that the enclosure (1) constitutes a cooling zone for the heated parts and that the agent which circulates is a protective gas.   Device according to Claim 4, characterized in that the cooling zone is combined with a heat treatment furnace which is also traversed by a protective gas flow, and that the protective gas, burned by the air supply, forms curtains of flames at the entrance of the oven and at the exit of the cooling zone.   Device according to any one of the claims   I to 5, characterized in that the valves (7) (8) are actuated by servomotors (18) (19) which themselves are regulated by a temperature sensor (17).   Device according to claim 6, characterized in that the temperature sensor (17) is arranged in a channel connected to the outlet (3) of the cooling zone (1) and detects the   temperature of the gas burned in the flame curtain.