Method for placing an oven for heat-treating preforms on standby

Patent metadata

Field	Value
Publication number	US-9381676-B2
Application number	US-201113877396-A
Country	US
Kind code	B2
Filing date	Oct 6, 2011
Priority date	Oct 11, 2010
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A method for placing an oven ( 12 ) for heat-treating preforms ( 13 ) into standby, including: a device ( 16 ) for conveying the preforms ( 13 ); at least one heating lamp ( 22 ); at least one heat-accumulation element ( 24, 26 ); and an electronic unit for controlling the heating lamps ( 22 ), characterized in that the method includes, in series: a first switching-off step (E 1 ) which is triggered when a stop in production is determined, and in which the heating lamps ( 22 ) are completely switched off; and then a second temperature-maintaining step (E 2 ) which is triggered after the first step (E 1 ), and in which the heating lamps ( 22 ) are activated at a predetermined intensity in order to reheat the accumulation elements ( 24, 26 ).

First claim

The invention claimed is:

1. A method for placing an oven ( 12 ) for heat-treating thermoplastic material preforms ( 13 ) on standby during a temporary cessation of production, the oven ( 12 ) including:
a device ( 16 ) for conveying the preforms ( 13 ) that moves the preforms ( 13 ) through the oven ( 12 );
at least one heating lamp ( 22 ) that is adapted to emit infrared radiation when it is switched on, each heating lamp ( 22 ) being disposed along the route of the performs ( 13 );
at least one heat-storage element ( 24 , 26 ) that is made from a material having a high thermal capacity, the storage element ( 24 , 26 ) being adapted to be heated by the heating lamp ( 22 ); and
an electronic unit for controlling the heating lamps ( 22 );
the method comprising the sequential steps of:
a switching-off step (E 1 ) of placing the oven in a standby condition for the temporary cessation of production, which switching-off step (E 1 ) is triggered when a cessation of production is determined, and during which switching-off step (E 1 ) the heating lamps ( 22 ) are switched off completely; and
a temperature-maintaining step (E 2 ) of preventing an internal temperature of the oven from falling too far by maintaining the oven at a reduced temperature during the standby condition, the reduced temperature being a temperature sufficient in order to prevent a need for warming up the oven ( 12 ) when the oven leaves the standby condition and when restarting production, the temperature-maintaining step (E 2 ) being triggered after the switching-off step (E 1 ), wherein during the temperature-maintaining step (E 2 ), the heating lamps ( 22 ) are switched on at an intensity determined so as to heat the storage elements ( 24 , 26 ) sufficient that the storage elements maintain the oven at the reduced temperature.

2. The method claimed in claim 1 , wherein the method is repeated from the switching-off step (E 1 ) until the oven ( 12 ) is returned to production.

3. The method claimed in claim 1 , wherein the switching-off step (E 1 ) ends after a predetermined first or switching-off duration (D 1 ).

4. The method claimed in claim 3 , wherein the temperature-maintaining step (E 2 ) ends after a predetermined second or switching-on duration (D 2 ).

5. The method claimed in claim 1 , characterized in that the switching-off step (E 1 ) ends when the temperature of the storage element ( 24 , 26 ) is less than or equal to a first or lower threshold temperature (T 1 ).

6. The method claimed in claim 5 , wherein the temperature-maintaining step continues until the temperature of the storage element ( 24 , 26 ) is greater than or equal to a second or upper threshold temperature (T 2 ).

7. The method claimed in claim 5 , wherein the temperature of the storage element ( 24 , 26 ) is measured by a probe ( 28 ) which is disposed near or in the storage element ( 24 , 26 ).

8. The method claimed in claim 1 , wherein the oven ( 12 ) includes ventilation means that are adapted to be controlled by the electronic control unit, the ventilation means being deactivated during the switching-off step (E 1 ) and activated during the temperature-maintaining step (E 2 ).

9. The method claimed in claim 1 , wherein when the cessation of production exceeds a limit duration, the method is stopped and the heating lamps ( 22 ) are switched off completely.

10. The method claimed in claim 2 , wherein the switching-off step (E 1 ) ends after a predetermined first or switching-off duration (D 1 ).

11. The method claimed in claim 2 , wherein the switching-off step (E 1 ) ends when the temperature of the storage element ( 24 , 26 ) is less than or equal to a first or lower threshold temperature (T 1 ).

12. The method claimed in claim 6 , wherein the temperature of the storage element ( 24 , 26 ) is measured by a probe ( 28 ) which is disposed near or in the storage element ( 24 , 26 ).

13. The method of claim 1 , wherein,
the heating lamps ( 22 ) are located along the route of the performs ( 13 ) at locations between the preforms and the storage elements ( 24 , 26 ) and emit the infrared radiation towards both the preforms and the storage elements ( 24 , 26 ), and
the storage elements ( 24 , 26 ) are reflectors positioned so that during the production the infrared radiation emitted from the heating lamps in a direction away from the preforms is reflected back by the reflectors in a direction towards the preforms.

14. The method of claim 1 , wherein the heating lamps ( 22 ) are located along the route of the performs ( 13 ) at locations between the preforms and the storage elements ( 24 , 26 ) and emit the infrared radiation towards both the preforms and the storage elements ( 24 , 26 ).

15. The method of claim 1 , wherein the storage elements ( 24 , 26 ) are blocks that are disposed vertically between two adjacent heating lamps.

16. The method of claim 1 , wherein the storage elements ( 24 , 26 ) are comprised of a ceramic material.

17. The method of claim 13 , wherein the storage elements ( 24 , 26 ) are comprised of a ceramic material.

18. The method of claim 14 , wherein the storage elements ( 24 , 26 ) are comprised of a ceramic material.

19. The method of claim 1 , wherein the storage elements ( 24 , 26 ) are comprised of a ceramic material with a thermal conductivity less than 30 W.m −1 .K −1 .

20. The method of claim 1 , wherein during the temperature-maintaining step (E 2 ), the heating lamps ( 22 ) are switched on at 50% intensity so as to heat the storage elements ( 24 , 26 ) sufficient that the storage elements maintain the oven at the reduced temperature.

Assignees

• Derrien Mikael
• Bernier Pascal
• Danel Laurent
• Sidel Participations

Inventors

• Derrien Mikael
• Bernier Pascal
• Danel Laurent

Classifications

• B29C49/78

  Measuring, controlling or regulating · CPC title

• B29C49/68

  Ovens specially adapted for heating preforms or parisons · CPC title

• B29C49/6418 Primary

  Heating of preforms · CPC title

• B29C2035/0822

  using IR radiation · CPC title

• B29B13/02 Primary

  by heating (B29B13/06, B29B13/08 take precedence) · CPC title