Energy efficient blow molder control
Blow molder system and associated method optimizes the performance, energy efficiency and/or operating costs of the blow molder. A blow molder controller executes a system model that relates blow molder input parameter changes to the characteristics of containers generated by the blow molder. Equipped with energy and/or operating cost data for operating the blow molder, the blow molder controller can select a set of blow molder input parameter changes for the blow molder that: drives the containers produced by the blow molder toward desired container characteristics, in an efficient amount of time, and in cost effective manner, considering the energy costs involved in implementing the changes.
1. A blow molder system comprising:
a blow molder that produces containers from preforms, wherein the blow molder comprises:
a plurality of molds; and
a blow molder sensor for sensing an operating condition of the blow molder;
a container inspection system for inspecting the containers produced by the blow molder ; and
a blow molder controller that is in communication with the blow molder and the container inspection system, wherein the blow molder controller is configured to:
receive outputs from the blow molder sensor and the container inspection system;
determine a set of blow molder input parameters for the blow molder that drives the containers generated by the blow molder toward a desired container characteristic, wherein the set of blow molder input parameters are determined based on:
the outputs from the container inspection system and blow molder sensor; and
operating cost data for the blow molder, wherein the operating cost data comprises energy costs for operating the blow molder; and
output the set of blow molder input parameters to the blow molder for implementation by the blow molder,
wherein the blow molder controller determines the set of blow molder input parameters by determining the set of blow molder input parameters that optimize a plurality of factors, wherein the plurality of factors comprise:
satisfaction of the desired container characteristic; and
operating costs for the blow molder to implement the set of blow molder input parameters, wherein the operating costs are based on the operating cost data for the blow molder.
2. The blow molder system of claim 1 , wherein the plurality of factors further comprise an expected scrap rate for containers produced by the blow molder until the containers reach the desired container characteristic.
3. The blow molder system of claim 1 , wherein the operating cost data for the blow molder comprises incremental costs to make changes to the operating parameters of the blow molder, wherein the incremental costs are based, at least in part, on the energy costs for operating the blow molder.
4. The blow molder system of claim 3 , wherein the blow molder controller determines the set of blow molder input parameters by performing steps that comprise:
determining multiple sets of blow molder input parameters, wherein each of the multiple sets of blow molder input parameters drives the containers generated by the blow molder toward the desired container characteristic; and
determining an incremental cost associated with each of the multiple sets of blow molder input parameters, wherein the incremental costs are determined based on current operating parameters of the blow molder and the energy costs for the blow molder, wherein the current operating parameters of the blow molder are sensed, at least in part, by the blow molder sensor; and
selecting a first set of blow molder input parameters from the multiple sets of blow molder input parameters based on the incremental costs associated with each of the multiple sets of blow molder input parameters.
5. The blow molder system of claim 1 , wherein the set of blow molder input parameters comprises a change to at least one of the following operating parameters of the blow molder:
pre-blow timing;
pre-blow pressure;
power levels for individual heater elements of the plurality of molds;
preform temperature set points;
stretch rod timing; and
blow pressure.
6. The blow molder system of claim 1 , wherein the container inspection system comprises a material distribution sensor system for sensing a material distribution characteristic of the containers.
7. The blow molder system of claim 6 , wherein the material distribution sensor system comprises at least one emitter-detector pair, wherein an emitter of the emitter-detector pair emits light energy and a detector of the light energy pair detects light energy.
8. The blow molder system of claim 7 , wherein the at least one emitter-detector pair comprises a plurality of emitter-detector pairs, wherein the emitter of each emitter-detector pair emits light energy toward the containers and the detector of each emitter-detector pair senses light energy that passes through at least one sidewall of the containers.
9. The blow molder system of claim 6 , wherein the container inspection system further comprises a crystallinity sensor for sensing a crystallinity level of the containers.
10. The blow molder system of claim 1 , wherein the container inspection system comprises a crystallinity sensor for sensing a crystallinity level of the containers.
11. The blow molder system of claim 1 , wherein the blow molder sensor comprises a sensor selected from the group consisting of:
an oven temperature sensor;
individual mold temperature sensors for the plurality of molds; and
a blow pressure sensor.
12. The blow molder system of claim 1 , wherein the desired container characteristic comprises a desired container sidewall thickness.
13. The blow molder system of claim 1 , wherein the desired container characteristic comprises a desired crystallinity level.
14. The blow molder system of claim 1 , wherein the energy costs comprise electricity costs for a plant where the blow molder is located.
15. The blow molder system of claim 1 , wherein the blow molder blows a fluid into the preforms to form the containers.
16. The blow molder system of claim 1 , wherein the operating cost data for the blow molder comprise a cost of expected scrap containers produced by the blow molder.
17. The blow molder system of claim 16 , wherein the cost of expected scrap containers is determined, in part, based on a time for the blow molder to produce containers that satisfy the desired container characteristic.
18. The blow molder system of claim 1 , wherein the plurality of factors that the blow molder controller optimizes to determine the set of blow molder containers further comprises a time for the blow molder to produce containers that satisfy the desired container characteristic.
19. The blow molder system of claim 1 , further comprising an ambient temperature sensor for sensing an ambient temperature of a plant in which the blow molder is located, wherein the blow molder controller is further configured to determine the set of blow mold parameters based on temperature data from the ambient temperature sensor.
20. The blow molder system of claim 19 , further comprising a moisture sensor for sensing a moisture level of the plant in which the blow molder is located, wherein the blow molder controller is further configured to determine the set of blow mold parameters based on moisture level data from the moisture sensor.
21. The blow molder system of claim 1 , further comprising a plant moisture sensor for sensing a moisture level of a plant in which the blow molder is located, wherein the blow molder controller is further configured to determine the set of blow mold parameters based on moisture level data from the plant moisture sensor.