Oven for the thermal conditioning of preforms and control method of an air cooling device fitted to such an oven

Patent metadata

Field	Value
Publication number	US-10493686-B2
Application number	US-201514976942-A
Country	US
Kind code	B2
Filing date	Dec 21, 2015
Priority date	Jun 2, 2010
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

An oven ( 10 ) for the heat treatment of preforms and a method for operating an air-cooling device ( 42 ) fitted to such an oven includes controlling elements ( 58 ) to vary the cooling air flow rate onto the body ( 18 ) and bottom ( 20 ) of the preforms ( 12 ) along the heating path.

First claim

The invention claimed is:

1. A method for operating a cooling device ( 42 ) in a heat treatment oven ( 10 ) for heat treatment of thermoplastic preforms ( 12 ) each comprising a first part ( 14 , 16 ) having a definitive shape and a second part ( 18 , 20 ) having a wall with internal and external surfaces, the oven including:
a heating path through the oven that is followed by the preforms ( 12 ), the heating path including infrared radiation (IR) lamps along at least part of the heating path, the infrared radiation (IR) lamps heating the second part ( 18 , 20 ) of the preforms,
a first lengthwise portion of the heating path being located at an inlet portion of the heating path, a second lengthwise portion of the heating path being connected to the first portion, a third lengthwise portion of the heating path being connected to the second portion, and a final lengthwise portion of the heating path being located at an outlet portion of the heating path, and
a cooling system ( 36 ) comprised of a first cooling device ( 40 ) that air-cools the first part ( 14 , 16 ) of the preforms and a second cooling device ( 42 ) that air-cools the second part ( 18 , 20 ) of the preforms,
said second cooling device ( 42 ) comprising plural fans ( 52 ), each fan driven by a respective motor, each fan operative to deliver a flow rate of cooling air to a respective separate one of the lengthwise portions of the heating path, and flow rate varying means ( 58 , 64 ) for selectively and separately setting the flow rate of cooling air delivered by each of said plural fans to the second part of the preforms in the respective separate lengthwise portions of the heating path, said flow rate varying means comprising a respective independently operable speed variator ( 58 ) associated with each of said plural fans,
the method comprising:
before the preforms travel along the heating path,
determining the respective cooling air flow rates to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in each of the respective separate lengthwise portions of the heating path, at least on a basis of a temperature gradient to be reached through a thickness of the wall of said second parts as the preforms travel along the heating path, wherein the temperature gradient to be reached is such that the temperature of the internal surface of the wall is greater than or at least equal to the temperature of the external surface of the wall, and
subsequently to the determining step, selectively and separately operating the flow rate varying means ( 58 , 64 ) to selectively set the determined respective cooling air flow rates to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the respective separate lengthwise portions of the heating path;
as the preforms travel along the heating path, cooling the second parts of the preforms using the determined, selectively set, respective cooling air flow rates in the respective separate lengthwise portions of the heating path; and
operating the first cooling device ( 40 ) that air-cools the first part ( 14 , 16 ) of the preforms independently of the second cooling device ( 42 ) that air-cools the second part ( 18 , 20 ) of the preforms.

2. The method according to claim 1 , further comprising:
measuring at least one of an internal temperature and an external temperature of the wall of the second part ( 18 , 20 ) of the preforms ( 12 ) so as to produce a signal representative of the at least one of the internal and external temperatures or of the gradient corresponding to a difference between the internal and external temperatures.

3. The method according to claim 2 , further comprising, as the preforms travel along the heating path, based on a result of said measuring step, changing the determined, selectively set, respective cooling air flow rates in the respective separate lengthwise portions of the heating path by repeating the determining and selectively setting steps based on the signal.

4. The method according to claim 1 , further comprising:
setting a power of the infrared radiation (IR) lamps ( 30 ) so as to vary, along the heating path, the heating power delivered to the second parts ( 18 , 20 ) of the preforms ( 12 ).

5. The method according to claim 1 , further comprising, as the preforms travel along the heating path, not changing the determined, selectively set, respective cooling air flow rates in the respective separate lengthwise portions of the heating path.

6. The method of claim 1 , wherein in the determining step, the determination of the temperature gradient to be reached as the preforms travel along the heating path defined by each respective module is based on a function of a position occupied by the preform along the said heating path.

7. The method of claim 6 , wherein the determining step determines that:
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the second lengthwise portion of the heating path is set to be greater than the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the first lengthwise portion of the heating path,
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in third lengthwise portion of the heating path is set to be less than the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the second lengthwise portion of the heating path, and
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in final lengthwise portion of the heating path is set to be greater than the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the second lengthwise portion of the heating path.

8. The method of claim 7 , wherein the determining step determines that:
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the first lengthwise portion of the heating path is set to correspond to a non-zero amount less than 30% of a maximum power of the motor of the fan,
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in second lengthwise portion of the heating path is set to correspond to a value between 30-60% of a maximum power of the motor of the fan,
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in third lengthwise portion of the heating path is zero, and
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in final lengthwise portion of the heating path is set to correspond to a value between 80-100% of a maximum power of the motor of the fan.

9. The method of claim 1 , wherein the determining step determines that:
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the second lengthwise portion of the heating path is greater than the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the first lengthwise portion of the heating path,
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in third lengthwise portion of the heating path is less than the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in the second lengthwise portion of the heating path, and
the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms ( 12 ) in final lengthwise portion of the heating path is greater than the cooling air flow rate to be delivered to said second parts ( 18 , 20 ) of the preforms

Assignees

• Sidel Participations

Inventors

• Derrien Mikael

Classifications

• B29C2035/0822

  using IR radiation · CPC title

• B29C49/6445

  through the preform length · CPC title

• B29K2105/258

  Tubular · CPC title

• B29C2035/1658

  using gas · CPC title

• F27D15/02

  Cooling · CPC title