Title of Invention

A CONTROL SYSTEM FOR HUMIDIFICATION PLANT IN TEXTILE INDUSTRY

Abstract

The present invention relates to a control system for humidification plant in textile industry, comprising a. closed loop humidity control module comprising a humidity sensor (1) and a control circuit (2) connected to air supply unit of a humidification chamber; b. temperature control module provided with a sensor (4) connected to a direction control pneumatic valve (6) and temperature control circuit (5) connected to damper of said plant; c. air flow control module provided with a speed control having variable speed drives (14) for regulating an supply to said chamber. The present invention also relates to a method of energy saving for a humidification plant in textile industry.

Full Text

The present invention relates to a control system for humidification plant in textile industry. Introduction: Humidification plants are usually employed in the textile industries for humidifying the rooms, which houses the textile machinery. Humidification plants are designed for peak heat load condition that prevails in summer. Fans of different sizes are provided as part of humidification control system. Humidification plant is the second largest power consuming component next to spinning section and accounts for nearly 15% to 20% of the power bill of a textile unit. Out of the total energy consumed by the humidification plant, 60% to 70% is utilized by the fans only. It is noticed that in winter and in the early morning substantially less power is used by the unit as the load on the humidification plants is reduced due to decrease in the transmitted heat load. In addition, the existing method of varying the airflow by damper control in the humidification plant is energy intensive. Therefore the object of the present invention is to provide an alternate method to conserve energy from the existing energy consumption level without affecting the performance in respect to process, quality and environment. Background of the invention: The existing automated control system for humidification plant in Indian textile industry comprises a fresh air damper which is controlled by means of signals received from the humidistat and thermostat placed inside the department to monitor humidity and temperature respectively. The control system works either pneumatically using compressed air at a pressure of about 1.5 bars or electronically. Suitably, either pneumatic cylinder or electric motors are used as actuators for the control dampers. A flow control valve is used in the air washer section to control the humidity of air passing through the air washer by means of which both flow and pressure of water is varied. The required level of humidity and temperature is automatically maintained by controlling the quantity of humidified air by means of the control dampers and the quantity of water sprayed in the air washer section through a closed loop control system. In the case of automated humidification plants, the required level of humidity and temperature are automatically maintained by controlling the quantity of humidified air by means of the control dampers and the quantity of water sprayed in the air washer through a closed loop control system. In the case of manually operated humidification plants the control dampers as well as the pump in the air washer section are operated manually depending on the prevailing outside climate. Since damper control is used in the existing method, there is a considerable amount of power loss in the system. In view of the above described disadvantage, it is an object of the present invention to provide a control system to be employed without altering the existing humidification plant which does not affect the performance with respect to process, quality and environment. Summary of the invention: The present invention relates to an energy saving control system for a humidification plant in textile industry, comprising: i) humidity control module, ii) temperature control module and iii) air flow control module. By incorporating the above three modules in the existing humidification plants, there is considerable amount of energy saving achieved in the textile industries. The energy saving control system of the present invention aims at reducing the energy consumption of the supply air fans, exhaust air fans and water spraying pumps used in the humidification plants by using humidity control, temperature control and air flow control modules which employ variable speed drives. The system can be incorporated in any humidification plant i.e., manually operated or automatic plant. With this development, it is possible to save substantial amount of energy in the existing condition without affecting the performance. The other advantages of the present control system are a. The system can be incorporated in any humidification plant i.e. manually operated or automated plant b. High-grade sensor ensures error free operation c. Provision to bypass the system d. Reduced in-rush current for the motors of supply air fans, exhaust air fans and water spraying pumps e. Significant reduction in energy consumption of supply air fans, exhaust air fans and water spraying pumps f. It can be easily retrofitted in the existing humidification plants g. The operation of the control system is very simple h. Automatic operation avoids manned control i. Flexibility is offered for users to change automatic mode to manual j. The quality and production of the yarn/fabric in textile mills does not get affected because of the incorporation of the newly developed system in the existing humidification plant. Accordingly the present invention relates to a control system for humidification plant in textile industry, comprising a) closed loop humidity control module comprising a humidity sensor and a control circuit connected to air supply unit of a humidification chamber; b) temperature control module provided with a sensor connected to a direction control pneumatic valve and temperature control circuit connected to damper of said plant; c) air flow control module provided with a speed control having variable speed drives for regulating an supply to said chamber. This system can also be used in the humidification plants in other sections of textile industry such as preparatory and spinning unit. Brief description of the drawings: Fig 1:- is a schematic diagram of the humidity control module. Fig 2:- is a schematic diagram of the temperature control module. Fig 3> is a schematic diagram of the air flow control module. Detailed description of the drawings: Fig.l- illustrates the humidity control module. The humidity control module comprises a high quality and fast response humidity sensor (1), which is mounted in the existing humidification plant. This humidity sensor (1) is connected through a humidity control circuit (2) with the pump (3) in the air washer section. If the required relative humidity of say 90% is not available after eliminator sheets, the air washer pump (3) is switched on to boost the humidity level. If the relative humidity is more than 95%, the humidity sensor (1) will switch off the pump (3). In this closed loop humidity control system, the pump will run only when humidity enhancement is required. In a preferred embodiment, variable speed drives can also be employed to vary the speed of the pump (3), instead of switching on/off the water pumps. Fig.2- illustrates the details of the temperature control module. The temperature control module employs components like pneumatic cylinders, direction control valves, controllers and actuators. The pneumatic cylinder actuates the control dampers of the fresh air damper (7), exhaust air damper (8) and recirculation damper (9). Using the direction control pneumatic valve (6), the position of these dampers is controlled in such a way that either the damper is in fully opened or fully closed condition. The outside atmospheric temperature is measured using a temperature sensor (4) and a control circuit (5) is used to actuate the solenoid operated direction control pneumatic valve. If the atmospheric temperature is less than say 20°C, the fresh air damper (7) and exhaust air dampers (8) will close fully with complete opening of recirculation damper (9) resulting 100% recirculation of air in the humidifying chamber. On the other hand, if the atmospheric temperature is more than 20°C, the fresh air damper (7) and exhaust air damper (8) will open fully with complete closing of recirculation damper (9) thereby stopping air circulation in the humidifying chamber. Fig.3 - Illustrates the details of the airflow control module for varying the speed of the supply air fan, for controlling the airflow for the supply air fan and exhaust fan by variable speed drives. Two different power panels are present in this module which are attached to the existing humidification plant which includes a supply air fan (10), a air washer section (11), a flow control valve (12), a pump (13), a fresh air damper (18), a recirculation damper (19), an exhaust damper (20), rotary filter (21), dust collector (22) and a dust collecting chute (23). The two different power panels are made of variable speed drives (14), controllers and actuators - one for the supply air fan (10) control and another for the exhaust air fan (17) control. The closed loop control is actuated using the humidistat (15) and thermostat (16) and the speed of the supply air fan and exhaust fan are varied for maintaining the required humidity inside the department. When the atmospheric temperature and the humidity are high, the quantity of air delivered into the humidifying chamber will get decreased by means of humidistat (15). But, when there is a further increase in this limit, the thermostat (16) kept inside the chamber will override the humidistat and will increase the fan speeds of both the fresh air and exhaust fans by means of variable speed drives. The actual power consumption at different frequencies of variable speed drives was measured using an accurate clamp-on power meter. It was found that the quantum of energy saving possible by this system varies from 25% to 60% in the existing condition. We claim: 1. A control system for humidification plant in textile industry, comprising a) closed loop humidity control module comprising a humidity sensor (1) and a control circuit (2) connected to air supply unit of a humidification chamber; b) temperature control module provided with a sensor (4) connected to a direction control pneumatic valve (6) and temperature control circuit (5) connected to dampers of said plant; c) air flow control module provided with a speed control having variable speed drives (14) for regulating air supply to said chamber. 2. The control system as claimed in claim 1, wherein said humidity sensor (1) is fixed next to eliminators of said humidification plant and said control circuit (2) connects humidity sensor (1) with a pump (3) in an air washer section of said humidification plant. 3. The control system as claimed in claim 1, wherein said direction control pneumatic valve (6) is operated by a solenoid and said temperature control circuit is connected to fresh air (7), exhaust air (8) and recirculation dampers (9) of said plant. 4. The control system as claimed in claim 1, wherein said variable speed drives (14) has controllers and actuators for controlling a supply air fan (10) and an exhaust air fan (17). 5. The control system as claimed in claim 4, wherein the variable soeed drives (14) receives control signal from a humidistat (15) and thermostat (16). 6. A method of energy saving for a humidification plant in textile industry, comprising the steps of controlling the switching off/on of air washer pump by means of a humidity control module, regulating the control dampers of the fresh air, exhaust air and recirculation damper with temperature control module and controlling the speed of the supply air fan and exhaust fan with an air flow control module. 7. The method as claimed in claim 6, wherein the air washer pump is switched on/off based on the humidity sensed by the humidity sensor fixed next to the eliminator of said plant. 8. A control system for humidification plant in textile industry such as herein described with reference to the accompanying drawing.

Documents:

0648-che-2005-abstract.pdf

0648-che-2005-claims.pdf

0648-che-2005-correspondnece-others.pdf

0648-che-2005-description(complete).pdf

0648-che-2005-drawings.pdf

0648-che-2005-form 1.pdf

0648-che-2005-form 26.pdf

0648-che-2005-form 3.pdf

648-CHE-2005 AMENDED CLAIMS 02-04-2013.pdf

648-CHE-2005 EXAMINATION REPORT REPLY RECEIVED 02-04-2013.pdf