Method and apparatus for controlling removal of gaseous cryogen from a continuous tunnel type freezer wherein the cryogen and product to be frozen travel in counterflow heat exchange relation to minimize ambient atmosphere moving into the tunnel and out of the exhaust system with the exhausted gaseous cryogen.
This is a continuation of application Ser. No. 07/759,261 filed Sep. 13, 1991, now abandoned the Specification which is incorporated by reference herein.
The present invention discloses an apparatus for regulating chamber pressure in a process chamber by a closed-loop control method utilizing a pressure sensor, a pressure controller and an inverter for regulating the rotational speed of an exhaust blower such that the exhaust pressure in a factory exhaust conduit can be substantially controlled at a constant value. The present invention novel method and apparatus allows a more stable chamber pressure to be maintained in an APCVD or LPCVD chamber, while substantially reduces the possibility of particulate contamination on a throttle valve that is mounted juxtaposed to the process chamber and thus minimizing any back-fill contamination problems.
A method of cooling coated foods, particularly confectionery and baked goods, wherein the goods are moved by a conveyor belt through a cooling duct, and wherein air is used as the cooling agent. Alternatively, the goods are conveyed by a conveyor belt through a cooling duct above base plates forming heat exchangers, wherein a liquid cooling agent flows through the heat exchangers. The method includes adjusting a delta-T (actual value) between cooling agent exit and cooling agent entry for a certain product to be coated by regulating the cooling agent flow speed, entering this delta-T as nominal value in a computer as the parameter for further cooling of this product, and regulating the cooling agent entry temperature, particularly in the case of production interruption or restart of production, by the difference determined in the computer between the delta-T determined as the nominal value and the actually measured value.
An apparatus for cooling articles (4), especially articles being covered with a chocolate mass, includes a cooling channel (1) and a conveyer belt (2) for transporting the articles (4) through the cooling channel (1). The articles (4) in the cooling channel (1) are exposed to a temperature profile (31) extending approximately from the entrance (5) to the exit (6) of the cooling channel (1). A first cooling circuit through which a first cooling medium (14, 24) flows is connected to a first cooling stretch (12). The first cooling medium (14, 24) enters the first cooling stretch (12) in the middle region (11) of the cooling channel (1) at a first entering temperature (17, 30). A first temperature sensor (18, 25) is arranged in the region of the entrance (5) of the cooling channel (6) for sensing the temperature of the first cooling medium (14, 24). A first control device (37, 51) controls the temperature of the first cooling medium (14, 24) in the sense of keeping the temperature substantially constant in the region of the entrance (5) of the cooling channel (1) and in the sense of changing the first entering temperature (17, 30) of the first cooling medium (14, 24) in response to the load of articles (4) being located in the cooling channel (1). Correspondingly, there is a second cooling circuit and a second cooling stretch (13). A second temperature sensor (23, 27) is arranged in the region of the exit (6) of the cooling channel (1) for sensing the temperature of the second cooling medium (24, 26). A second control device (46, 58) correspondingly controls the temperature of the second cooling medium (24, 26).
A method and apparatus for using a cryogen cooling articles, particularly having applications for chilling extrusions, food, and similar articles, utilizing dispersion of liquid cryogen into a feed chamber wherein it is substantially vaporized and then circulated through a cooling chamber containing the article to be cooled. A circulation device can circulate the vaporized cryogen through the cooling chamber at a variably controllable velocity to enhance the cooling efficiency using the principle of forced air convection and to provide improved temperature control in the system.
A method and apparatus for using vaporized liquid cryogen to cool articles, particularly extrusions, utilizing dispersion of liquid cryogen into a chamber wherein it is substantially vaporized and then circulated through cooling circuits in a tool for cooling the tool, or an article such as an extrusion which is to be cooled by the tool. Additionally, the tool may itself be disposed in a cooling chamber in which vaporized cryogen is circulated to cool the tool and the article.
