Autoclave

An autoclave for heating, under pressure, separate objects, the autoclave comprising:

• a pre-transfer chamber and a post-transfer chamber, means selectively to communicate the pre-transfer chamber with, and to isolate the pre-transfer chamber from, an operative cavity of the autoclave, means selectively to communicate the post-transfer chamber with, and to isolate the post-transfer chamber from, the operative cavity of the autoclave, means for selectively pressurizing respectively the pre-transfer chamber and the post-transfer chamber and means for selectively depressurizing respectively the pre-transfer chamber and the post-transfer chamber,
• loading means suitable for loading the objects into the pre-transfer chamber, unloading means suitable for unloading the objects from the post-transfer chamber, transport means suitable for transporting the objects from the pre-transfer chamber through the autoclave cavity to the post-transfer chamber, temperature measuring means in the operative cavity to measure temperature repeatedly, at predetermined time intervals, in the autoclave, a computer for computing sterilization values F.sub.o for objects being sterilized in accordance with the formula ##EQU7## in which T is a convenient time interval;
• t.sub.i is the average temperature of a product in the th time interval;
• t.sub.ref is a reference temperature;
• n is determined such that the sterilization value F.sub.o is bigger than a pre-defined set-point value,
• and for comparing the computed value for F.sub.o with a predetermined base value for F.sub.o, the unloading means being controllable in response to the result of comparing the computed and base values for F.sub.o, to unload the object only when the computed value for F.sub.o is at least equal to the base value for F.sub.o.

A method of operating an autoclave for sequentially heating separate objects under pressure and cooling said objects, the method comprising:

• providing an autoclave having a pre-transfer chamber and a post-transfer chamber, means selectively to communicate the pre-transfer chamber with, and to isolate the pre-transfer chamber from, an operative cavity of the autoclave, means selectively to communicate the post-transfer chamber with, and to isolate the post-transfer chamber from, the operative cavity of the autoclave, pressurizing means for selectively pressurizing respectively the pre-transfer chamber and the post transfer chamber and depressurizing means for selectively depressurizing respectively the pre-transfer chamber and the post-transfer chamber, said pressurizing means comprising a first restrictive passage having first valve means between the operative cavity and the pre-transfer chamber and a second restrictive passage having second valve means between the operative cavity and the post-transfer chamber, said depressurizing means comprising a third restrictive passage having third valve means extending from the pre-transfer chamber and a fourth restrictive passage having fourth valve means extending from the post-transfer chamber;
• loading an object to be treated into the autoclave by, sequentially, isolating the pre-transfer chamber from the operative cavity, depressurizing the pre-transfer chamber by opening the third valve means in the third restrictive passage, introducing the object into the pre-transfer chamber, isolating the pre-transfer chamber from atmosphere, pressurizing the pre-transfer chamber via said first restrictive passage between the operative cavity and the pre-transfer chamber by opening said first valve means of said first restrictive passage, communicating the pre-transfer chamber with the operative cavity and transferring the object from the pre-transfer chamber into the operative cavity;
• and unloading another object which has been treated from the autoclave by, sequentially, isolating the post-transfer chamber from atmosphere, pressurizing the post-transfer chamber via said second restrictive passage between the operative cavity and the post transfer chamber by opening said second valve means of said second restrictive passage, communicating the post-transfer chamber with the operative cavity, transferring said other object into the post-transfer chamber, isolating the post-transfer chamber from the operative cavity, depressurizing the post-transfer chamber by opening the fourth valve means of the fourth restrictive passage of the depressurizing means and removing said other object from the post-transfer chamber.

A method of operating an autoclave for sequentially heating separate objects under pressure and cooling said objects, the method comprising:

• providing a composite autoclave which includes a first vessel and a second vessel, an operative cavity of the autoclave being defined as sub-cavities in said first and second vessels, a pre-transfer chamber adjacent the first vessel, a pressure tight closure which is selectively openable to communicate the pre-transfer chamber with the first vessel and which is selectively closeable to isolate the pre-transfer chamber from the first vessel, pressurizing means for selectively pressurizing the pre-transfer chamber and depressurizing means for selectively depressurizing the pre-transfer chamber, a post-transfer chamber adjacent the second vessel, a pressure tight closure which is selectively openable to communicate the post-transfer chamber with the second vessel and which is selectively closeable to isolate the post-transfer chamber from the second vessel, pressurizing means for selectively pressurizing the post-transfer chamber and depressurizing means for selectively depressurizing post-transfer chamber;
• loading an object to be treated into the autoclave by, sequentially, isolating the pre-transfer chamber from the operative cavity depressurizing the pre-transfer chamber, introducing the object into the pre-transfer chamber, isolating the pre-transfer chamber from atmosphere, pressurizing the pre-transfer chamber, communicating the pre-transfer chamber with the operative cavity and transferring the object from the pre-transfer chamber into the operative cavity;
• progressively moving objects from the pre-transfer chamber through the first vessel, heating said objects in the first vessel, intermittently transferring said objects to the second vessel, cooling said objects in the second vessel and progressively moving said objects through the second vessel towards the post-transfer chamber;
• and
• unloading another object which has been treated from the autoclave by, sequentially, isolating the post-transfer chamber from atmosphere, pressurizing the post-transfer chamber, communicating the post transfer chamber with the operative cavity, transferring said other object into the post-transfer chamber, isolating the post-transfer chamber from the operative cavity, depressurizing the post-transfer chamber and removing said other object from the post transfer chamber.

An autoclave for heating, under pressure, separate objects, the autoclave comprising:

• a pre-transfer chamber and a post-transfer chamber, means selectively to communicate the pre-transfer chamber with, and to isolate the pre-transfer chamber from, atmosphere and an operative cavity of the autoclave;
• means selectively to communicate the post-transfer chamber with, and to isolate the post-transfer chamber from, atmosphere and the operative cavity of the autoclave;
• pressurizing means for selectively pressurizing respectively the pre-transfer chamber and the post transfer chamber;
• depressurizing means for selectively depressurizing respectively the pre-transfer chamber and the post-transfer chamber, said pressurizing means comprising a first restrictive passage having first valve means between the operative cavity and the pre-transfer chamber and a second restrictive passage having second valve means between the autoclave cavity and the post-transfer chamber, said depressurizing means comprising a third restrictive passage having third valve means extending from the pre-transfer chamber and a fourth restrictive passage having fourth valve means extending from the post-transfer chamber;
• loading means suitable for loading the objects into the pre-transfer chamber;
• unloading means suitable for unloading the objects from the post-transfer chamber;
• and transport, means suitable for transporting the objects from the pre-transfer chamber through the autoclave cavity to the post-transfer chamber.

An autoclave for heating, under pressure, separate objects, the autoclave being a composite autoclave comprising:

• a first vessel and a second vessel, an operative cavity of the autoclave being defined as sub-cavities in said first and second vessels, a pre-transfer chamber adjacent the first vessel, a pressure tight closure which is selectively openable to communicate the pre-transfer chamber with the first vessel and which is selectively closeable to isolate the pre-transfer chamber from the first vessel, pressurizing means for selectively pressurizing the pre-transfer chamber and depressurizing means for selectively depressurizing the pre-transfer chamber, a post-transfer chamber adjacent the second vessel, a pressure tight closure which is selectively openable to communicate the post-transfer chamber with the second vessel and which is selectively closeable to isolate the post-transfer chamber from the second vessel, pressurizing means for selectively pressurizing the post-transfer chamber and depressurizing means for selectively depressurizing post-transfer chamber, an intermediate transfer chamber arranged to operate in the manner of a lock intermediate the first vessel and the second vessel, means selectively to communicate the intermediate transfer chamber with each of the first vessel and the second vessel and to isolate the intermediate transfer chamber from each of the first vessel and the second vessel, loading means suitable for loading the objects into the pre-transfer chamber, unloading means suitable for unloading the objects from the post-transfer chamber, and transport means suitable for transporting the objects from the pre-transfer chamber through the operative cavity to the post-transfer chamber.