domingo, 30 de octubre de 2016

Tubería de fundición en edificación: ofrecen alta resistencia y reacción al fuego

Ante la entrada en vigor del marcado CE, Saint-Gobain PAM España, a la vanguardia de la innovación en todos sus productos y siempre por delante de las exigencias normativas, se convierte en la primera empresa que incorpora el marcado CE en tuberías de evacuación. Son dos los requisitos básicos e imprescindibles para la adecuación del producto al CTE.

Las tuberías SMU S y SMU Plus cumplen con la exigencia normativa de EI =120 min usando lana de roca en los sectores de compartimentación de incendios, llegando a obtener hasta un EI=180 min. También existe un dispositivo de fundición para diámetro 100, el cual se instala directamente como un accesorio más y cumple con el ensayo y clasificación enunciados anteriormente.

La tubería de fundición SMU S y SMU PLUS ha obtenido la Clasificación de Reacción al Fuego para el conjunto del sistema (juntas + tuberías + accesorios) de A2 s1 d0, lo que permite que pueda ser utilizada en cualquier zona de los edificios sin necesidad de ningún cálculo adicional, teniendo una absoluta seguridad en su comportamiento de reacción al fuego. Presenta unas prestaciones superiores a cualquiera material siendo prácticamente incombustible.

Cumpliendo con el compromiso adquirido con las tecnologías limpias y el cuidado y respeto al medioambiente, la fundición utilizada en evacuación no emite gases tóxicos en su combustión y se fabrica con materiales no nocivos para el medioambiente procedentes de componentes férricos reciclados en un 96%. Por tanto, las tuberías de fundición SMU S y SMU PLUS de Saint-Gobain PAM España son 100% reciclables.
Las características mecánicas medidas en los tubos SMU S y SMU PLUS son superiores a las exigencias de la norma UNE EN 877 y a las que presentan otros fabricantes. Esto es posible gracias a la fabricación de las tuberías mediante centrifugación y proceso de De Lavaud, asegurando unas características mecánicas como resistencia a la tracción de 300 MPa y al aplastamiento en anillo de 470 MPa. Además, las tuberías presentan un revestimiento exterior compuesto por una pintura de apresto acrílica anticorrosiva de un espesor medio de la película seca 40 micras y un revestimiento interior epoxi bi-componente con un espesor de la película seca 130 micras

Cada una de las gamas SMU tienen un ámbito de utilización diferente, utilizándose SMU S en conducciones aéreas y vaciado de sanitarios para la evacuación de aguas usadas, residuales y pluviales; y SMU PLUS en conducciones aéreas y vaciado de sanitarios para la evacuación de aguas grasas, industriales y residuos agresivos (cocinas colectivas, hospitales, clínicas, laboratorios, industrias, etc.) así como también en redes enterradas para todas las evacuaciones de aguas de los edificios y redes privativas enterradas para conexión a las arquetas.

El agua: la economía circular y la huella hídrica como herramientas necesarias para una gestión eficaz

En este artículo se van a poner en relieve algunas de esas cifras y datos que deben de hacernos estar alerta, muy alerta, y abandonar el estío continuo frente al devenir, debido a que vivir el presente, pensando que es mejor que el pasado sin pensar que debe de haber un “mañana” provoca que tengamos la obligación de resaltar algunas herramientas necesarias para dotar a la sociedad de un recurso básico e imprescindible poniendo el acento en los once objetivos de Desarrollo Sostenible, que se debatieron en la pasada Cumbre de las Naciones Unidas sobre el Desarrollo Sostenible del año 2015.
El objetivo 6 hace mención al agua limpia y saneamiento, mientras que el objetivo 11 focaliza la atención en las ciudades y comunidades sostenibles. Unas ciudades que aún conservan el mayor de los desafíos en sus periferias – no obstante, el arquitecto italiano y senador vitalicio, Renzo Piano (ganador del premio Pritzker, el nobel de la arquitectura), dedica su sueldo como senador para estudiar cómo mejorar las periferias italianas con un equipo contratado de jóvenes arquitectos – que alojan aún a 828 millones de personas. Unas ciudades que suponen el 2% del planeta y que consumen entre el 60 y el 80% de la energía, y provocan el 75% de las emisiones de CO2. Esa descontrolada urbanización ha ejercido una descomunal presión sobre el abastecimiento de agua potable, sobre la necesaria depuración de las aguas y la falta de ella sobre todo y la salud pública, pues hoy día más de un millón y medio de niños mueren al año por enfermedades contraídas por el agua.
Pero entonces, la primera cuestión sería, ¿es sostenible un mundo de 7.000 millones de habitantes, donde desde el año 2007 más de la mitad de la población vive en las ciudades? El director británico Peter Weber y Stephen Emmot de Microsoft y profesor invitado en la Universidad de Oxford se lo preguntaron haciendo la estimación de que en el año 2100 seríamos 10.000 millones, e hicieron un documental intentando “despertarnos” de la siesta, acentuando la cuestión de hacia dónde vamos y si es sostenible un crecimiento demográfico tan desmedido. En el apartado relacionado con el líquido elemento, nos indican que aún a fecha de hoy, existen 1.000 millones de personas sin acceso a agua potable de “calidad” y apuntan que un 70% del agua potable se destina a fines agrícolas. Y nos dejan entrever un nuevo concepto de ‘agua oculta’, al que regresaremos un poco más tarde.
Tabla 1. Número de personas que sufren una escasez de agua baja, moderada, significativa y severa durante un número determinado de meses por año, para el año medio en el período 1996 -2005.
La tabla anterior pone de manifiesto y revela que Weber y Emmot llevan razón en su documental titulado ‘10.000 millones’ y que solo un cambio de paradigma y de mentalidad nos puede “despertar” a tiempo, y como subrayan los autores del artículo referenciado, Mekonnen y Hoekstra, la escasez de agua dulce se aprecia como un riesgo en incremento, cuando tres cuartas partes de la población mundial vive por debajo de las condiciones mínimas al menos una vez al mes (la mitad en India y China).
Viajando desde las islas británicas hasta la tierra del tulipán, nos encontramos con un joven profesor de la Universidad de Twente en Enschede (al este de los Países Bajos, casi en la línea fronteriza alemana), Arjen Hoekstra, que en el año 2002, tuvo una idea brillante. Pensó que sería interesante medir qué cantidad de agua es necesaria para fabricar un producto, véase un pantalón vaquero, una camiseta de algodón o un alimento. Y además calculó el agua que se contamina con motivo de la fabricación de dichos alimentos o productos en la cadena de producción (tabla 2). Y a la sumatoria de dichos volúmenes le dio el nombre de ‘Water Footprint’ (Huella Hídrica). Este gurú de la gestión eficiente de las masas de agua nos desvela que un 90% del agua potable mundial se dedica para fines agrícolas, y si tenemos en consideración que sólo entre un 1-4% es dedicado a consumo humano, tenemos que poner el foco en mejorar la innovación tecnológica en los campos y cultivos, debido a que el modo actual provoca estas ‘externalidades negativas’ haciendo que los campos sean auténticos sumideros de agua que se distribuye sin ningún control.














Tabla 2. Huella hídrica de algunos productos y alimentos. Fuente: www.waterfootprint.org
Es necesario, por lo tanto, analizar los procesos de producción, los rendimientos hídricos de las industrias, incentivar que las industrias reduzcan su huella hídrica, de tal manera que provoque un cambio de mentalidad y toma de concienciación definitiva, subraya el profesor Hoekstra, porque además, la mayoría de los alimentos son importados desde países donde sufren la escasez de agua indicada con anterioridad.
Aunque bien es cierto que en una economía globalizada, se pueden obtener productos más baratos donde el agua no es valorada o apreciada, y en muchos casos se desperdicia, porque puede tratarse de un país húmedo o porque el agua es “regalada” o “subvencionada” por parte de los que conforman el último eslabón del la gestión del ciclo integral del agua, y que están en contacto con los ciudadanos, empresas, agricultores, etc., nos indica Hoekstra, reafirmándose en que en una economía circular la huella hídrica es 0. Y en este contexto aparece otra herramienta, que es la Economía Circular, que puede definirse como una ciencia social que estudia la asignación eficaz y eficiente en términos de sostenibilidad de los factores productivos generando un proceso de producción o prestación de servicios, que no conlleva la existencia de externalidades negativas para el ecosistema. Insertando este concepto en la política europea, podemos afirmar tal y como nos indica la Fundación Ellen MacArthur, que el PIB de la Unión Europea podría crecer un 11% en el horizonte de 2030, mientras que podía escalar hasta el 27% para el 2050, frente a los pobres crecimientos actuales del 4% y del 15% previstos, con nuestro sistema económico lineal. Y desde las Instituciones Europeas han apostado por este cambio de paradigma, para estimular el cambio hacia la economía circular y fomentar dicho crecimiento económico más sostenible y que cree nuevos puestos de trabajo (estiman sobre unos 2 millones), así como aumentar la competitividad.
Profundizando en este concepto aplicado a la gestión del Ciclo Integral del Agua, debemos “obligar” a nuestros dirigentes a cerrar el ciclo con la puesta en marcha de las estaciones depuradoras de aguas residuales necesarias para cumplir la Directiva Europea, sin más moratorias, pues como nos indica el VII informe de la CE, aún no se ha llegado al 100% del tratamiento de las cargas contaminantes – y lo que es más grave, aún hay importantes capitales europeas que no hacen un tratamiento adecuado de sus efluentes residuales, por lo que aún no se puede cumplir con lo que indica la CE en su paquete sobre Economía Circular, sobre las medidas a tomar para facilitar la reutilización del agua, incluyendo una propuesta legislativa sobre requisitos mínimos del agua reutilizada, por ejemplo para el riego y la recarga de acuíferos.
Sería fundamental apostar por insertar de forma perpetua la reutilización del agua en el ciclo integral, porque provocaría que se dependiera de la explotación de acuíferos, que continuáramos dependiendo de la pluviometría con nuestras prerrogativas, y de tal manera que, aminorando la huella hídrica en nuestros procesos tecnológicos e industriales, reduciendo esa “agua oculta” a la que antes hacíamos referencia, y dotando a nuestros campos de la innovación tecnológica necesaria para reutilizar cada gota de agua, porque como nos dice, Antonio Castillo, hidrogeólogo de la Universidad de Granada y del CSIC, “el agua es vida, es paisaje, es cultura, es ocio, es recreo, es turismo, bebida y comida y motor económico, …” y de esta manera, poder dar un giro completo a nuestro sistema productivo y económico, siendo partícipes de un cambio de mentalidad en aquellos que deben dirigir el rumbo de esta nave llamada Tierra.
Y volviendo a Puccini y a su magistral ópera Turandot, …’All’alba, vinceró’. Venceremos cuando amanezca un nuevo rostro en todos los que nos dedicamos, de uno u otro modo, a gestionar un recurso tan vital y necesario como es el Agua, porque aunque sea complicado y difícil, el esfuerzo habrá merecido la pena, y porque como nos dejó escrito Igor Stravinsky en su Poética Musical, “aquello que me libera de una dificultad me quita una fuerza, cuanto más nos comprometemos con las obligaciones, más nos liberamos de las cadenas que atan el espíritu”. Cuanto más difícil sea nuestra meta, más obligados estamos todos a remar hacia el mismo objetivo. Lograr un mundo más habitable y más justo. Ojalá que al alba estemos totalmente “despiertos”.

BOQUILLAS PULVERIZADORAS

La boquilla pulverizadora transforma la energía total de un líquido en energía cinética. Esta última es utilizada para descomponer el líquido en pequeñas partículas y distribuirlas uniformemente de acuerdo con la distribución deseada.
En ciertos casos, la energía cinética es utilizada para conferir al líquido una mayor penetración. En otros, la boquilla permite obtener un caudal variable en función de la presión, la cual se puede fácilmente calcular gracias a las tablas del catalogo.

Caudal

El caudal se determina por el diámetro interno de paso así como por la presión ejercida.
En general la relación entre el caudal y la presión es la siguiente:

Siendo Q1 y P1, el caudal y la presión conocidas. Q2 es el caudal resultante en función de la presión escogida P2. Todas las tablas del catálogo están basadas en el agua.
Para los líquidos cuya densidad especifica es distinta de 1, es preciso multiplicar por los factores de conversión indicados en la tabla inferior:

Tipos de boquillas

Disponemos de una amplia gama de boquillas, que permiten resolver cualquier problema de pulverización. A continuación se describen las categorías principales:










  • Aspersión Cono Vacio: tipo A
    Las partículas se distribuyen uniformemente para formar la superficie exterior de un cono. Por tanto, el área cubierta por el chorro sobre un plano perpendicular será una circunferencia cuyo diámetro será proporcional a la distancia de la boquilla y al ángulo de la misma.
  • Aspersión Cono Lleno: tipo B
    En este tipo de chorro, la parte interna del cono está uniformemente constituida por partículas líquidas. El área cubierta por la boquilla, es perpendicular al chorro, y en este caso, es un círculo cuyo diámetro está en función de la distancia y del ángulo de aspersión.
  • Aspersión Chorro Plano: tipo C
    En este caso, el área cubierta es perpendicular al chorro con una forma de elipse alargada cuya anchura es función de la distancia entre la boquilla y el área a cubrir. La dimensión longitudinal es función de la distancia así como del ángulo de aspersión.
  • Atomizadores: tipo E
    En estas boquillas, el aire comprimido se mezcla con el líquido, produciendo una atomización muy fina.
    En las diferentes tablas, se pueden escoger las combinaciones de aspersión (Boquilla del liquido + boquilla del aire) que mejor satisfaga sus necesidades especificas.

Angulo de aspersión

El ángulo de aspersión es medido generalmente cerca del orificio. Aumentando la distancia de medición, se pierde precisión a causa de la gravedad y de las condiciones ambientales. Es conveniente igualmente saber que un aumento de la viscosidad del producto reduce el ángulo de aspersión.
En las tablas siguientes se indican las coberturas teóricas a diferentes distancias en función al ángulo de aspersión.


Diámetro de las gotas (granulometría)

Los principales factores que influyen sobre el diámetro de las gotas son el caudal, la presión y el tipo de boquilla. Generalmente un aumento del caudal a presión constante comporta un aumento del tamaño de las gotas. Aumentando la presión, se reduce el diámetro de las gotas, aumentando el ángulo de aspersión. Las gotas más finas se obtienen con atomizadores neumáticos y las más voluminosas con las boquillas de cono LLENO. La tabla inferior indica, para cada forma de chorro, el diámetro medio de las gotas en relación al caudal mínimo y máximo, a una presión constante de 3 bar.

Impacto

La fuerza de impacto de una pulverización depende principalmente del caudal, de la presión y de la forma del chorro. Los impactos más importantes se obtienen con las boquillas de chorro rectilíneo y de chorro plano, y las más débiles con las boquillas de cono lleno y cono vacío de gran ángulo de aspersión.

Duración de la boquilla

El efecto de desgaste producido sobre el orificio de la boquilla, impacta un aumento del caudal y, generalmente, un deterioro de la forma del chorro. En términos comparativos se puede afirmar que, bajo idénticas condiciones de funcionamiento, el acero inoxidable tiene una vida cinco veces superior al latón.

Clasificación medida pulverización


Codificaciones para el catálogo

El material estándar utilizado para la construcción de nuestros productos es el que sale en los cuadros de cada modelo.
Eurospray puede proporcionar inyectores con diferentes materiales de acuerdo a la norma requerida.
Los productos Eurospray son identificados con códigos alfanuméricos de 11 caracteres.

Método de identificación para los INYECTORES / BOQUILLAS

  • El primer carácter es la letra que identifica el tipo de material (véase el cuadro 1).
  • El segundo dígito es el número que se corresponde con el tipo de rosca (1/8" - 1/4" - 3/8" etc. ref. Tabla 2).
  • El tercer carácter identifica si el tipo de rosca de conexión es macho (M) o hembra (F), el cual no se apunta cuando no hay ningún tipo de rosca de conexión (como modelos DH-BG) y, a continuación, no se tendrán en cuenta en el cuadro 2.
  • El cuarto y quinto caracteres son para identificar el modelo correspondiente a la familia según el "catálogo de las boquillas" (por ejemplo, chorro plano - C2 o C3E).
  • El sexto y séptimo caracteres corresponden al diámetro del agujero de acuerdo con el catálogo de boquillas (por ejemplo, para el modelo C2-03 de 1,1 mm. de diámetro, se corresponde con la escala de 3 bar. a 1,20 l/min. de caudal) Para el modelo MCE3 son el séptimo y el octavo carácter. I.
  • El octavo y noveno número de código (o en orden alfabético según el sistema más adelante), hasta un máximo de once CODIGOS, determinar el ángulo correspondiente a CADA BOQUILLA según en el cuadro del catálogo de las boquillas I.
Por lo tanto, para ordenar un archivo adjunto con la boquilla de latón 1/8" Macho C2-03/110° el código modelo se describirá: O0MC203A.
Las siguientes tablas de referencia.

NB: Para las boquillas de alta presión, los modelo MC-C y HP, no se especifica los materiales, por lo que el código de la parte de la rosca o modelo (Ejemplo: C4-020 -1HP022).
* Sólo para boquillas de chorro plano.

Para pedidos

EJEMPLO DE CODIFICACIÓN PARA UNA BOQUILLA DE CHORRO PLANO DE LATÓN MODELO EN EL CATÁLOGO PAG 34 MC2 1/8"MC2-03-110°

jueves, 27 de octubre de 2016

Cálculo de cargas térmicas

CLASE 178º HIGROMETRIA HUMIDIFICACION ADIABATICA EVAPORATIVOS

Safety alert follows ac “explosions”

AUSTRALIA: A spate of incidents resulting in air conditioning engineers being seriously burned has prompted a safety alert from Australian health and safety authorities.
The safety report was issued by SafeWork NSW, the workplace health and safety regulator for New South Wales, after what was described as a number of serious incidents as a result of the ignition of refrigerant/oil mixtures during servicing.
In the reported cases, workers were using an oxy-acetylene torch to unsweat the copper fittings when replacing a compressor. Although using non-flammable R22, it’s believed that residual pressure in the system caused the refrigerant and oil mixture to be released from the pipe joint, which contacted the oxy-acetylene torch and started a flash fire.

In March 2016, SafeWork NSW confirmed that two workers at a Lake Macquarie, NSW, business sustained burns shortly after one of the workers separated a copper pipe from the discharge outlet of the compressor in a commercial air conditioner using an oxy-acetylene torch.
An earlier incident this year in Melbourne, Victoria, in which an air conditioning unit exploded causing burns to the face, chest and legs of an engineer, is also thought to be connected.
Although failing to recover refrigerant breaches environmental regulations, SafeWork also warns that attempting to break into a system before all residual refrigerant has been removed can cause a sudden release of refrigerant and oil mist, which will be flammable.
Heat from a naked flame will likely result in ignition of any expelled refrigerant and oil mist, and can cause trace amounts of refrigerant to decompose and generate highly toxic fumes.
SafeWork NSW observes that oxy-acetylene torches are commonly used to unsweat copper fittings but warns that this practice can be extremely hazardous and unsafe unless appropriate control measures are taken. It warns that refrigerant will remain in solution with compressor oil unless the refrigerant is completely recovered using a reclaim unit. Warming or agitating the system will also cause the refrigerant to evaporate, resulting in a rise in pressure.
In addition to ensuring the refrigerant is recovered before breaking into the system, it recommends ensuring the work area is well ventilated, and using pipe cutters rather than an oxy-acetylene torch.

Incidents of this kind and to this extent are rare in the UK but experts warn that such accidents can occur when work is carried out without due care and attention being applied to standard best practice.
“Any brazing or de-brazing should, of course, always be carried out after recovery of any excess gas in a system and after the introduction of an inert gas such as oxygen free nitrogen (OFN) into the pipework,” commented Graeme Fox senior mechanical engineer at UK contractors’ association BESA.
“OFN is used because it inhibits the oxidisation of the internal copper pipes and fittings, but it is important to also remember it expels oxygen from the internal system preventing flash ignition of hot oil – a particular problem when de-brazing welded connections on compressors upon replacement.
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“Hazards such as this should always be identified in the RAMS documents produced for work like this and risk reduction/elimination measures should then be taken to ensure accidents like this one are eliminated from normal working procedures.
“As our industry moves increasingly towards the use of flammable refrigerants it becomes ever more essential for technicians to be fully aware of risks like this and to use industry best practice at all times,” he added.
Stephen Benton, a director at UK training consultancy Cool Concerns, points out that the problem is not a new one, but says: “A competent technician will always be aware of the potential for fire during brazing operations not to mention toxic products of decomposition due to the oxy-acetylene flame if refrigerant vapour is present.
“When unbrazing, and after recovery of the refrigerant, the system should be open to atmosphere to avoid any pressure build up inside the system,” he said.
“Gloves and goggles should always be worn together with ensuring an adequate risk assessment has been carried out. A dry powder fire extinguisher should be on hand at all times during hot works and ideally OFN is purged through any pipework being brazed or unbrazed.”

sábado, 22 de octubre de 2016

exportación de cárnicos, condicones de trabajo

La Secretaría de Agricultura, Ganadería, Desarrollo Rural, Pesca y Alimentación (Sagarpa) otorga la certificación Tipo Inspección Federal (TIF) a través del Servicio Nacional de Sanidad, Calidad e Inocuidad Agroalimentaria (Senasica). Esto es posible gracias a un procedimiento meticuloso de inspección y supervisión de rastros y establecimientos industriales, dedicados a producir, almacenar, sacrificar, procesar y distribuir todo tipo de cárnicos y sus derivados.
El objetivo del certificado, según indica el licenciado Sergio Nava, gerente de Promoción de la Asociación Nacional de Establecimientos TIF (ANETIF), no sólo es aumentar la cantidad de producción de carne, sino generar valor agregado a la producción que ya se genera en el país. “No tener esta certificación es desaprovechar mercados en cadenas de distribución, como los grandes supermercados. Además, el modelo de calidad hace más accesible el consumo de productos de calidad a un mayor número de habitantes en el país”, indica.
La creación del esquema TIF se planteó como un método para aumentar los estándares de calidad de todos los tipos de carne, así como para promover la reducción de riesgos de contaminación de sus productos, a través de la aplicación de sistemas de inspección por parte del personal capacitado oficial, o autorizado, que se dedica a este sector.
Desde hace 60 años, ha logrado mantener a las empresas procesadoras de cárnicos a la vanguardia, debido a que el sello TIF se ha convertido en requisito indispensable para exportar productos y subproductos cárnicos. Los beneficios que trae con ella, según el licenciado Nava, se dirigen tanto al consumidor como a las empresas procesadoras de carne.
“La certificación TIF trae consigo una serie de beneficios para el consumidor, quien cuenta con la garantía de calidad sanitaria con la que fue elaborado el producto. Esto porque se establece que el alimento está libre de contaminantes, o sustancias que pudieran dañar la salud. Además, para las empresas que procesan cárnicos bajo los lineamientos TIF es más fácil movilizar su producción de una zona a otra del país; sus productos son mejor cotizados en el mercado interno, además de que tienen la posibilidad de acceder al mercado internacional, ya que los establecimientos TIF son los únicos elegibles para exportar productos y subproductos cárnicos mexicanos”, enfatiza el Gerente de Promoción de la ANETIF.

Vigilancia en la inocuidad

Para que un producto obtenga la certificación TIF, el Senasica vigila el proceso en su totalidad; desde las instalaciones, la construcción del establecimiento, la maquinaria, equipo, indumentaria y enseres que se utilizan. En sus inicios, este tipo de establecimientos solamente enlataban carne, no obstante, ahora abarca diversas labores, según la especialidad del producto, por lo que vigilan todo el proceso: el sacrificio, corte y deshuese, hasta el almacenamiento y procesamiento de cárnicos.
De los 360 establecimientos que hay en el país, 122 están dedicados al sacrifico de ganado bovino, porcino, ovino, caprino y equino, además de aves como pollos y codornices. De éstos surgen otros establecimientos dedicados al procesamiento y almacenamiento de productos cárnicos.
Según la Asociación Internacional de Almacenes Refrigerados (GCCA, por sus siglas en inglés), México cuenta con 4.07 millones de m³ de almacenes refrigerados destinados a productos alimenticios, cifra que lo coloca detrás de Brasil, que tiene 5.71 millones de m³ y de Estados Unidos, que cuenta con 107.3 millones de m³, por lo que la infraestructura de almacenes dedicados a la conservación de cárnicos aún debe crecer.
Entre las normas de sanidad con las que cuenta la certificación TIF, resalta la NOM-004-ZOO-1996, que marca los límites permisibles de residuos tóxicos y procedimientos de muestreo en grasa, hígado, músculos y riñones de aves, bovinos, caprinos, cérvidos, equinos, ovinos y porcinos, además de embutidos, y así garantizar que la carne esté libre de sustancias prohibidas, como el clembuterol o de cualquier otra.
Esta norma, en conjunto con las NOM-008-ZOO-1994, la NOM-009-ZOO-1994 y la NOM-033-ZOO-1995, indica los procesos bajo los cuales debe llevarse a cabo el manejo de cárnicos. En el caso de la refrigeración, la cantidad de agua y de sustancias de conservación y aderezos que tenga el paquete de carne que se está refrigerando debe ser mínima, pues parte de la calidad de la carne depende de su estado físico, y no se podrá congelar un paquete de carne que tenga un exceso de aquéllas.
En el caso de las normas que deben respetar rastros y centros de almacenamiento, la NOM-194-SSA1-2004 Etapas de la Refrigeración Industrial será el esquema a seguir en el tratamiento de frío de cárnicos. En ella se incluye:
  • Proceso de enfriado
  • Almacenamiento de enfriado
  • Proceso de congelado

Almacenamiento de congelado

Esta regulación comprende establecimientos que se dediquen a la refrigeración y congelación de carne de res, cerdo, caballo y conejo, mientras que para la carne de pollo se lleva un proceso distinto.
En el caso de los productos provenientes de aves, éstos tendrán que pasar por un proceso de preenfriado, el cual puede ser en seco o por inmersión, donde la temperatura se mantenga debajo de los 4 °C.
Sin embargo, todos los productos deberán pasar por un proceso de control de temperatura, después de la etapa de sacrificio y antes de llegar al almacén, esto según el Senasica. Para ello, deberán respetar las siguientes prácticas:
  1. Las canales de carne deberán lavarse antes de ser introducidos en espacios de enfriamiento, ya sea que éstos sean tanques de congelación, cajas con aislamiento térmico o paquetes de producto
  2. Todo equipo de enfriamiento por agua debe vaciarse, limpiarse y sanitarse después de cada jornada
  3. Las instalaciones tienen que contar con aparatos de medición de temperatura en los que se monitoree el rango de calor permitido, según el producto por almacenar
  4. El hielo a utilizar en los procesos de preenfriamiento deberá ser producido mediante un proveedor que garantice el control microbiológico y fisicoquímico
  5. Los productos frescos deberán respetar los límites de frío hasta que éstos lleguen a manos del consumidor (ya sea de refrigeración, congelación o refrigeración en seco)

Inversión en infraestructura

La necesidad de frío para los distintos procesos de producción de carne es evidente. Por ello se ha impulsado el crecimiento de establecimientos TIF. Según Sergio Nava, “el Senasica, en 2010, invirtió 176 millones de pesos en beneficio de 3 mil 950 productores de este tipo de establecimientos, con estos recursos se emprendieron 43 proyectos de infraestructura, que generaron 200 empleos y beneficiaron a 30 mil productores de cárnicos”.
Es importante recordar que 46 % de la exportación de carne que se produce en el país, y que se envía a otras latitudes, proviene de estos establecimientos. La demanda de productos cárnicos seguirá creciendo y, con ello, la regulación de frío será más estricta, por lo que los proveedores de servicios logísticos que estén involucrados en el tema tendrán que crecer sus almacenes de refrigeración y congelación.

FUNCIONAMIENTO DE UN SISTEMA DE COMPRESION MULTIPLE COMPRESORES DE DOBL...

FUNCIONAMIENTO DE UN SISTEMA DE COMPRESION MULTIPLE COMPRESORES DE DOBL...

jueves, 20 de octubre de 2016

HFCs flood Europe despite phase down

EUROPE: Refrigerant manufacturer Honeywell has repeated claims that European HFC imports are increasing despite the F-gas phase down.
Earlier this year, Honeywell claimed that over 10 million tonnes of CO2 equivalent HFCs were illegally imported into the EU in 2015 – the first year of the phase down when the allocation was 182.5 million tonnes of CO2 equivalent. This year is supposed to see a 7% reduction but Honeywell claims some countries are now importing as much as 2.5 times as much as they were pre-phase-down.
Dr Patrick Amrhein, Honeywell’s fluorine products marketing director for EMEA, said: “This is a major issue we are facing.”
Having recently run the numbers again on import statistics, he said: “What we can see is the amount of refrigerant coming from China into the European Union increasing year-over-year. When you look at the phase down mechanism this should not happen.”
He also claims that the problem seems to be with certain countries. “Traditional importers like the Netherlands, France, UK, Belgium, these countries are more or less stagnating or are on a small decline. What’s new is that countries such as Poland, Hungary, Greece, the Balkan areas, there you see increases compared to previous years of 140-160%. The interesting question is who sits there that holds all the quota?” he mused.
“We see a disconnect between the legislation and its implementation at a national level,” Dr Amrhein said in May. “I don’t think there is currently a system in place which allows the national customs authorities to really check if an importer has quota or if the importer who does have quota has exceeded the amount of imports they can bring in.”
According to the F-gas regulation, the consequences for producers and importers exceeding their allocated quota is a deduction of double the excess from the company’s quota the following year.
BELGIUM: One of the leading refrigerant manufacturers has claimed that over 10 million tonnes of CO2 equivalent HFCs were illegally imported into the EU in 2015.
Last year was the first year that the European Union’s phase down under the F-gas regulations came into force, allocating registered companies a quota from the total 182.5 million tonnes of F-gas allowed to be placed on the market.
Honeywell maintains that this amount has been exceeded by what it describes as illegal imports. If true, the illegal amount is equivalent to more than 5% of the total allocation and based on CO2 equivalents would represent, for example, well over 2,500 tonnes of R404A or 7,700 tonnes of R134a.
The concerns are also backed by another leading refrigerant supplier Chemours who said that they, too, had seen market indications of illegal imports.
Honeywell says it has based its estimated calculations on publicly available sources, such as export data from China, and compared these with EFCTC (Cefic) data. Honeywell has also heard of instances of companies without quota bringing in material and offering it for sale.
“As Honeywell is a significant market player, we also used our own estimations of imports of the biggest market players,” Dr Patrick Amrhein, Honeywell’s fluorine products marketing director for EMEA, told the Cooling Post. “This resulted in a figure showing material which cannot be assigned to any market player – and therefore has to come to the market outside of the quota.”
However, the real scale of the trade in illegal material could be far higher and does not include any refrigerant shipments that may have been smuggled into Europe or mis-declared.
“The amount of material coming into Europe far exceeds what should be coming in,” said Dr Amrhein. “I think 10 million tonnes is a conservative figure. Our estimation is that it is larger.”
A total of 413 companies were assigned quotas in 2015, 334 of them were new entrants. Each quota holder’s figures are audited at the end of March each year. The consequences for producers and importers exceeding their allocated quota is a deduction of double the excess from the company’s quota the following year.
Earlier this year, the Cooling Post revealed that imports of HFC refrigerants doubled in 2014, suggesting huge stockpiling in the run-up 2015 to the introduction of F-gas quotas.
Lack of control
Honeywell has also raised concerns at what it perceives as a lack of control or implementation at customs points.
“We see a disconnect between the legislation and its implementation at a national level,” said Dr Amrhein. “I don’t think there is currently a system in place which allows the national customs authorities to really check if an importer has quota or if the importer who does have quota has exceeded the amount of imports they can bring in.”
The concerns over the potential for illegal imports are shared by Chemours. “We have seen market indications of illegal imports as mentioned by Honeywell,” said Lene Stosic, Chemours’ senior communications manager, EMEA. “We share the commitment to supporting the F-gas industry in the successful implementation of the cap and phase down.”
Authorised dealer programme
To reassure the market, Honeywell has implemented an Authorised Dealers programme to help purchasers ensure they are buying refrigerants that comply with the European F-gas regulations.
“This programme is part of Honeywell’s ongoing efforts to help customers ensure they are using refrigerants and other materials that comply with this new regulation,” said Dr Patrick Amrhein. “By buying from a Honeywell Authorised Dealer, customers can avoid putting their businesses at legal risk of violating the regulation by using an illegal refrigerant. Honeywell is continuing to build awareness of the risks and legal consequences of using illegally imported refrigerants, and is working closely with EU authorities to actively prevent illegal imports to the EU market.
“We are not the policemen of the industry, we are just responding to requests from our customers who want to buy genuine high quality material that is fully compliant with the F-gas regulations,” Dr Amrhein maintained.
EUROPE: Shocking new figures reveal evidence of huge European stockpiling of HFC refrigerants in advance of the 2015 F-gas quotas.
The startling figures for 2014, just released by the European Environment Agency, show that imports of HFC refrigerants into Europe almost doubled to 122,781 tonnes (260.9Mt CO2‑equivalent) in 2014, the year before quotas under the European F-gas regulations were introduced.
This huge stockpile is thought to be the reason why refrigerant prices, particularly for the higher GWP gases, have not risen as predicted by many industry experts.
While bulk imports of fluorinated gases had been declining from 2010 to 2013, HFC bulk imports in 2014 were approximately 90% above 2013 levels, both by mass and CO2‑equivalent.
The figures are based on submissions by companies on the production, import and export of fluorinated greenhouse gases in the European Union for 2014, the first year of compulsory reporting under the new F-gas regulation 517/2014. 
Leaving aside the other fluorinated greenhouse gases (SF6, PFCs, etc), HFCs are said to account for about 95% of the increase in bulk imports and around 75% of all reported imports were destined for use as refrigerants for refrigeration, air conditioning and heating purposes.
Although supplies intended for use in air conditioning and refrigeration had been static or declining in recent years, 2014 saw a huge increase to 92,958 – a 73% increase on the previous year and a 36% increase on the peak year for HFC supply in 2010.
In contrast to the rise in imports, EU production of HFCs declined for the fourth consecutive year. Production measured in tonnes experienced a year-on-year decline of 15%, or 11% in terms of CO2‑equivalents, to 31,050 tonnes. Reportable HFC production in Europe was limited to just six HFCs – 134a, 365mfc, 143a, 32, 227ea and 23. The supply of the other 19 fluorinated gases used in the EU in 2014 was provided by imports.
Reporting of imports and production became compulsory in 2014 and led to a significant rise in reporting companies. For 2014, the number of reporting companies tripled compared with 2013 to 468. The European Environment Agency attributes the increase to the addition for the first time of importers of products and equipment containing reportable fluorinated gases and to new bulk importers of gases.





jueves, 13 de octubre de 2016

Compressor development boost for CO2




GERMANY: Bitzer has increased the capabilities of CO2 as a future-compliant refrigerant with a new compressor development launched at Chillventa this week.
The new six-cylinder Ecoline+ reciprocating compressor for transcritical CO2 applications is said to boast a number of key developments, These include a new higher efficiency motor technology and mechanical capacity control to increase full and part-load efficiency.
“We would like to make efficient CO2 technology simpler and easier to understand again, and thus significantly expand the range of applications with the forward-looking refrigerant,” said Rainer Große-Kracht, Bitzer’s chief technology officer. “The ability to provide refrigeration solutions that are reliable over the long term will require expanding access to CO2 technology. “CO2 is one of the refrigerants of the future – we at Bitzer believe that wholeheartedly,” he added.
The line-start permanent-magnet motor (LSPM) allows the compressor to be operated directly in networks with 50 or 60Hz. Bitzer says the incorporation of permanent magnets has made it possible to significantly increase motor efficiency in full and part-load operation. The technology has been undergoing testing at Bitzer and in selected systems out in the field for more than five years. The LSPMs will now be incorporated into the series production set for CO2 applications. These motors can be operated both directly in the network and in the familiar speed range with frequency inverters, says Bitzer.
In addition to accommodating operation with frequency inverters, the new Ecoline+ compressors can also be equipped with the new mechanical capacity control for the first time, enabling compressor operation with a refrigerating capacity between 10 and 100%. The capacity control, which can comprise one controller in two-cylinder compressors and up to three controllers in six-cylinder compressors, is adjusted just as it is with the well-known capacity control of HFC refrigeration compressors.
The intelligent operating concept of the CM-RC-01 IQ module, which comes as standard, also ensures optimal efficiency for the oil supply, the oil heater and the new CRII capacity control, which is specially developed for CO2 applications. The interplay between CRII and CM-RC-01 is said to allow the capacity to be adjusted virtually infinitely between 10 and 100%. The CM-RC-01 IQ module makes it very easy and inexpensive to integrate the Ecoline+ reciprocating compressor into a whole host of system configurations. The IQ module not only improves protective measures and options for monitoring compressors, but also expands their range of applications and thus offers users greater flexibility. This in turn makes it easier, for instance, to compensate for differences between summer and winter operation. The new capacity control is said to increase overall efficiency, as the CRII enables a more stable and higher suction pressure

sábado, 8 de octubre de 2016

USO DEL CO2


    From its pure thermo dynamical properties CO2 is not very well suited as refrigerant. However, CO2 has several unique thermo physical properties:
    • Very good heat transfer coefficient
    • Relatively insensitive to pressure losses
    • Very low viscosity

    In practical applications, the CO2 systems deliver very high performance, the main reasons being better heat exchange, very low pumping power when CO2 is used as a secondary fluid, and in cold climate the possibility of operating with a very low condensing pressure in the winter.

    The efficiency of systems with CO2 depends more on the application and the climate than with other refrigerants. For all refrigerants there is a decline in system efficiency with increasing condensing temperatures, and CO2 is among the refrigerants with the steepest drop. The good thermo-physical properties of CO2 can compensate to some extent, but there is a limit.

    CO2 has high energy content at higher temperatures, and when this heat can be reclaimed for heating sanitary water or similar application, the efficiency of the total system becomes very high.
  • Environmental Impact

    From an environmental perspective, CO2 is a very attractive refrigerant with zero ODP and a GWP of 1. It is a naturally occurring substance and abundant in the atmosphere.
  • Pressure and Temperature

    CO2 is a high-pressure refrigerant where high operating pressures are required for efficient operation. During standstill, the ambient temperature can reach and exceed the critical temperature and the pressure can exceed the critical pressure. Hence systems are typically designed to withstand pressures up to 90 bar, or sometimes even equipped with a small standstill condensing unit to keep pressures low.

    At the same time, CO2 has a low compression pressure ratio (20 to 50% less than HFCs and ammonia), which improves volumetric efficiency. With evaporation temperatures in the range of -55 ºC to 0 ºC, the volumetric performance of CO2 is for example four to twelve times better than that of ammonia, which allows compressors with smaller swept volumes to be used.

    The triple point and critical point of CO2 are very close to the working range. The critical point may be reached during normal system operation. During system service, the triple point may be reached, as indicated by the formation of dry ice when liquid containing parts of the systems are exposed to atmospheric pressure. Special procedures are necessary to prevent the formation of dry ice during service venting.
  • Material Interaction

    CO2 does not react with common metals or with Teflon®, PEEK, or neoprene components. However, it diffuses into elastomers and can cause swelling with butyl rubber (IIR), nitrile rubber (NBR), and ethylene-propylene materials (EPDM).

    The density of liquid CO2 is about 1.5 times that of ammonia, resulting in higher mass charge in evaporators, such as large plate chillers in large industrial systems. Higher density means higher oil circulation as well, which in turn requires effective oil separators for industrial systems.
  • Cost Efficiency

    CO2 is a by-product in a number of industries, so the price of CO2 is low. However, CO2 systems tend to be more expensive than traditional systems due to higher pressures (in transcritical systems) or increased complexity (in both transcritical and subcritical systems). Complexity of systems seems to be decreasing with the entrance of Booster systems and as the number of CO2 installations has increased, history has shown that the cost approaches the cost of the reference systems using HFCs.

    Secondary, large CO2 systems, especially in industrial refrigeration, may be less expensive to build than their glycol counterparts and thus offer lower initial and life-cycle costs.
  • Applications

    Unlike most other refrigerants, CO2 is used in practice in three different refrigeration cycles:
    • Subcritical (cascade systems)
    • Transcritical (CO2-only systems)
    • Secondary fluid (CO2 used as a volatile brine)

    The technology used depends on the application and the intended location of the system. There are a several applications where CO2 is attractive and already widely used today:

    • Industrial refrigeration. CO2 is generally used in combination with ammonia, either in cascade systems or as a volatile brine
    • Food/retail refrigeration
    • Heat pumps
    • Transport refrigeration

    Danfoss believes that CO2 will be the main refrigerant in multipack commercial refrigeration systems. The new F-gas regulation is a clear push in this direction.


jueves, 6 de octubre de 2016

HFC refrigerants are said to be rising at an annual rate of 16%

FRANCE: HFC refrigerants are said to be rising at an annual rate of 16% in developing countries, according to a new report.
The report by the Climate and Clean Air Coalition (CCAC) and the UN Environment OzonAction Branch, entitled National Hydrofluorocarbon (HFC) Inventories: A summary of key findings from the first tranche of studies, summarises the findings from Bangladesh, Chile, Colombia, Ghana, Indonesia and Nigeria.
The report claims that HFC use will rapidly rise in the coming decades unless more is done to curb their growth.
“Without a doubt, growing populations and economic development are exponentially increasing the demand for refrigeration and air conditioning,” said Helena Molin Valdes, head of the CCAC secretariat. “If we continue down this path, without developing alternatives to HFCs and more energy efficient appliances, we will put great pressure on the climate system.”
The CCAC says its 50 state partners strongly support the adoption of an ambitious HFC phase-down amendment to the Montreal Protocol at next week’s meeting in Kigali, Rwanda.  A communique released by the CCAC’s high level assembly said that the amendment should include an early freeze and rapid action to phase down HFCs. 
“Now is the time and Kigali is the place,” Molin Valdes said. “A HFC phase-down amendment will represent the biggest climate deal this year.”

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The country inventories outline opportunities to avoid growing HFC use and to phase down existing consumption. They show that there are significant differences among countries in terms of the sectors where HFC use is growing, with some countries having larger consumption in domestic or commercial refrigeration, and others in mobile or stationary air conditioning.
The inventories also show that out of the different chemicals R134a is the most common, accounting for an average of 80% of HFC use from 2011-2014 across the six countries. While R134a has a GWP of 1300, by 2020 the HFC blends, R401A (which has a GWP of 1300), R404A (GWP of 3300) and R507A (GWP of 3300) will have an increasingly larger share of the total. 
The CCAC will be organising a side event to present the main findings of this report on the margins of the Montreal Protocol Meeting of the Parties in Kigali, Rwanda on October 14

lunes, 3 de octubre de 2016

EXPLICACION DE UNA PLANTA DE FRIO PARA CONGELACION A CUATRO TUBOS

Realising the power of analysis



As we find ourselves midway through the Wimbledon Championships, there are many similarities between the latest innovations in the use of data in the sporting world and the cooling industry.
The power of data is without question. There is certainly beauty in the numbers. With increasing pressure on budgets and heightened emphasis on demonstrating return on investment (ROI), the ability to make decisions based on fact rather than perception or gut feeling has even greater significance.
Data therefore has to be seen as an ingredient which needs to be converted into value. Without context and analysis added to data, it is meaningless. Trends cannot be identified and operational efficiencies will never come to fruition.
The latest innovation launched at this year’s Wimbledon Championships is IBM’s SlamTracker. This innovation realises the potential of data and translates it into meaningful information to fans and players dynamically.
It puts enthusiasts at courtside, providing live updates on match scores, statistics, service speeds, aces and winners. Key information is delivered in real-time, providing an immediate, accurate and visual picture of a match as it unfolds. With SlamTracker IBM has not been afraid to demonstrate how technology can add to the fan experience.
SlamTracker’s Key to the Match application is a further example of the success of interpretation and visualisation of data. Predictive analytics technology is used to farm over 8 years of Grand Slam Tennis data, including 41 million data points, to determine patterns and styles for players when they win. Prior to each match, the system runs an analysis of competitors’ historical matches, statistics and comparable styles; this provides a player with a rich pool of information to help identify the best tactics and strategies to adopt to win the match.
The level of detail collected via the system brings an added dimension to the world of sport, providing data-driven, innovative broadcast coverage, engaging reporting and intelligent professional analysis.
Systems such as SlamTracker are dependent on data centre uptime. There are many similarities between systems like SlamTracker™ and the modern-day data centre building management system. An effective BMS should collect, package, analyse and distribute live data, providing at-a-glance dashboards to facility managers. A BMS will take the mass of information available and convert it into a usable format, giving you the capability to adapt, learn and grow to best manage and optimise facility performance.
Your BMS should be built on a consistent and reliable approach across sites. It needs to function to the same standard, using the same software and to the same definitions, providing you with a global standard for credible decision-making, based on fact. As with the innovation used at Wimbledon this year, your system needs to provide you with the complete picture of your data centre, with full visibility from building level to server level.
It could be argued that many data centre expansion projects could be avoided if organisations made better use of their existing IT resources and, with this in mind, a definitive strategic plan for your IT facility should invariably consider BMS as a top investment priority.
Put simply, data is the ingredient. With the right BMS, you can turn data into value and serve up match winning performance.

domingo, 2 de octubre de 2016

Five reasons for coil failure

5. Coil plugging
If filters are not changed or your HVAC coils cleaned properly in a timely manner, your coil will actually act as a filter. When dirt builds up on the coil, it will prevent heat transfer and can cause a 20% to 40% drop in performance. Dirt adds to the coil resistance and will absolutely cause your coil to fail prematurely.
4. Vibration
When your HVAC coils are installed near a moving piece of equipment, vibration can occur and cause leaks. The area where these leaks occur is very important and will clue you in to if the problem is vibration. If they are near the tube sheet and look like they are slicing through the tube, the coils should be isolated from the rest of the system to prevent vibration from causing damage. One way to combat this is by oversizing the tube sheet holes, but many manufacturers will not do this. Condenser coils are usually the most common victims of vibration.
3. Corrosive environment
This applies to both the air in the environment and inside the tubes. For instance, if there is something in the air that is corrosive, it will eat away at the copper tubes whether you have 0.020in wall or 0.049in wall. This is very common in areas where there may be salt in the air. To keep the costs down from going to a stainless-steel or cupro-nickel coil, we usually suggest coating the HVAC coils. Steam condensate and untreated water can cause corrosion within the tubes of HVAC coils as well. If you have a steam coil that has failed before the one year warranty, there’s a great chance corrosive agents are in the steam and it’s eating away at the copper tubes.
2. Freeze-ups
Most people think that when HVAC coils freeze, the water or condensate laying in the coil freezes into ice and it expands causing the tubes to bulge and eventually spring leaks. What really happens is the coil will freeze in multiple areas simultaneously and it’s the pressure between these areas that cause the tubes to swell and eventually burst. These are very easy to spot as the leaks will run the length of the tube rather than around the tube.  And be very careful when considering “freeze proof” coils.  If you remove 5-6in from the fin length to make it fit, the coil performance will suffer considerably.
1. System design
You would be amazed how many HVAC coils were never properly designed for their systems. If there was a problem with design, replacing the coil will only duplicate the problem. A high percentage of all our projects were because the HVAC coils were built incorrectly or was never designed right in the first place. Sometimes, owners want to improve performance by adding a couple rows, but don’t consider the air pressure drop or fluid pressure drop that comes with it.

Why use chiller glycol? Water. Is it more harmful than you think?

Getting the best out of glycol

Glycol is fundamental to the smooth operation of chillers and chilled water systems. Brent Hall, technical manager at ICS Cool Energy, offers nine top tips to ensure its best performance.
If specified incorrectly, Glycol can cause serious issues, including reduced heat transfer and corrosion. It’s not that difficult to save time and money by considering glycol specification and its effect on the operational life of a chiller system. Here are our top tips:
1. Never use automotive antifreeze
Automotive antifreeze is formulated for engine cooling rather than process or industrial cooling applications, so when it’s used for the wrong applications, it can cause problems with flow rates/pressures and reduced heat transfer. Many automotive antifreeze products are not glycol-based and contain other alcohols or glycerine, as well as silicate-based inhibitors, which can coat heat exchangers, attack pump seals, and form a gel, significantly affecting flow rates.
2. Only use inhibited glycol
Uninhibited glycol and water mixtures are very corrosive, often even more than plain mains water. Modern process and industrial glycols contain inhibitors alongside a pH buffer and biocide to protect against corrosion, scale formation, and rust. For a system to be contamination-free, it needs to be properly flushed, cleaned and sanitised before the addition of a suitable inhibited glycol and water mixture.
3. Don’t mix glycols
Different types and brands of glycol shouldn’t be mixed. Most modern glycols contain inhibitors and are dyed for identification.  If they are accidentally mixed, incompatibilities can lead to separation and/or reaction, resulting in gel formation which will clog filters, strainers, and pump suctions, as well as causing a deterioration in heat carrying and transfer properties.
4. Checking your local environmental rules
Some areas have regulations regarding the use and disposal of particular glycols and antifreeze solutions, concerning things such as ground structure, the water table and drainage. Be sure to consult your local authority to check the local environmental rules.
Businesses should also consider using a bio-glycol as an environmentally-friendly solution. Bio-glycols are derived from a sustainable source and are non-toxic, non-flammable, non-hazardous, and biodegradable.
5. Be aware of the effects of antifreeze on a system
Plain water is one of the most efficient pumped fluids for absorbing and carrying heat. However, when any other chemical is added to it, this ability is affected. Adding glycol will cause an increase in the fluid’s viscosity and density, and decrease its heat transfer and heat carrying properties. These property changes will not affect the overall functionality of your chilling plant and system as long as they are understood and discussed beforehand as they will result in a slightly reduced cooling capacity, an increased pumping power consumption and an increased fluid temperature difference (or an increased fluid flow).
6. Use the correct water
Most systems use ordinary mains ‘tap’ water, and while good for human consumption, it can be quite damaging to any chiller and its associated machinery and systems. The relative hardness (and hence the mineral content) varies from region to region, so applying the appropriate inhibitors and biocide is of vital importance. Even microbiological contaminants vary, giving a degree of unpredictability to using town mains water or any other uninhibited water source. Using a ‘pure’ water – distilled, demineralised, de-ionised or RO water – will remove this unpredictability.
On its own, pure water can be damaging to heat exchangers due to its tendency to attack certain metals within the chiller and water circuit. It also has very low conductivity which can be a problem with some chillers and systems. We recommend the use of pure water with a suitable (minimum 20%) inhibited glycol mix to give the ultimate system protection. The added glycol will increase the solution’s conductivity to a level which is compatible with both the system materials and any conductivity-based instrumentation.
It is important to never use continuously de-ionised/polished water or any pure water without inhibited glycol.
7. Consider Ethylene glycol in process/industrial applications
Ethylene-based glycol is the standard process/industrial antifreeze additive and can be used in any application where low toxicity is not a requirement. In terms of efficiency losses, ethylene glycol has the least effect on flow rate, heat transfer capability, and pressure loss. However, ethylene glycol has moderate acute oral toxicity so should not be used in applications where it may come into contact with potable water, food and/or beverage processing.
8. Consider Propylene-based glycol for food and beverage applications
Propylene-based glycols have low toxicity and are the ideal antifreeze additives for applications in the food and beverage industry and where user contact is a frequent occurrence. For extra reassurance, make sure it has been tested by the National Sanitary Foundation, which is shown by a NSF mark.  This is the assurance that the product is approved by an independent certification organisation that is valued by consumers, manufacturers, retailers, and regulatory agencies worldwide.
9. Maintain your chiller and system’s hygiene and fluid
The chilled water system and fluid used are the most important aspects to an installation. The water/glycol is the vehicle which collects the heat from the process and delivers it to the chiller, and the pipework is the road along which the fluid must travel. If either of these two are deficient in any way, the chiller’s operation will be compromised and the heat transfer capability will be reduced.
If necessary, filters/strainers should be installed and checked regularly, although the best policy is to tackle the source of any contamination. The chilled water system must be flushed, cleaned and sanitised prior to adding a new water/glycol solution. It must also be regularly sampled and tested to ensure there are no underlying or progressive contamination and/or corrosion issues.
For new, or recently cleaned and dosed systems, we recommend a test after three months of operation, including a comprehensive sample analysis. Thereafter, we recommend six monthly routine tests, along with regular visual examinations to check for colour and suspension.

Compressor training at Bitzer MK facility

UK: Compressor manufacturer Bitzer UK has hosted a three-day training programme for Airedale International staff prior to the Leeds manufacturer’s roll-out of a new chiller range.
Some 45 Airedale staff attended the sessions – a detailed technical briefing on Bitzer’s new CSVH range of compact inverter screw compressors – at Bitzer’s training facility in  Milton Keynes,
The training programme was part of Airedale’s preparations for its forthcoming roll-out of a new range of high performance, energy efficient chillers based on Bitzer’s CSVH screw compressor.
Marcus Levy, training manager and business development director at Bitzer UK, said: “The aim was to provide Airedale engineers with a comprehensive overview and technical understanding of the principles and application of the CSVH range. It provided a solid grounding in its application, installation, commissioning and service and maintenance.”
Bitzer UK opened its training centre in Milton Keynes last year. Courses cover a general introduction to compressor technology, plus detailed modules on screw compressors, reciprocating compressors, and condensing units. A key theme is UK requirements and applications.
Kevin Glass, managing director of Bitzer UK, says: “We were delighted with the response from Airedale. The aim is to provide a valuable blend of solid technical training in the principles behind the technology, plus practical help that addresses the real-world application issues that designers and engineers face every day in the course of their work.”
He added: “The UK has a reputation as a fairly advanced market, due to the sometimes unique requirements and technical approach required. At Bitzer UK we have a detailed understanding of these issues and how to deliver high efficiency, high performance solutions, and we share this knowledge and support delegates to help them to deliver for their own clients.”
The facility has capacity for up to 16 delegates at a time, enabling the Airedale training programme to run as three one-day sessions.
Other courses cover topics such as understanding and managing refrigerant glide, the regulatory framework and implications of the coming phase-down of high global warming F-gas refrigerants, and using online resources to support commissioning and servicing.
The Bitzer UK initiative is part of a wider training drive taking place within the Bitzer Group. The company recently completed its new international training centre, the Schaufler Academy, at Rottenburg-Ergenzingen in Germany in October last year.
For details, contact either Marcus Levy or Sam Buckell at infotech@bitzeruk.com

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